2516203981 has 4 divisors (see below), whose sum is σ = 2584209532. Its totient is φ = 2448198432.

The previous prime is 2516203969. The next prime is 2516203999. The reversal of 2516203981 is 1893026152.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 956664900 + 1559539081 = 30930^2 + 39491^2 .

It is a cyclic number.

It is not a de Polignac number, because 2516203981 - 2¹⁵ = 2516171213 is a prime.

It is a super-2 number, since 2×2516203981² = 12662564948000496722, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37), and also a Moran number because the ratio is a prime number: 68005513 = 2516203981 / (2 + 5 + 1 + 6 + 2 + 0 + 3 + 9 + 8 + 1).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2516203981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2516203901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34002720 + ... + 34002793.

It is an arithmetic number, because the mean of its divisors is an integer number (646052383).

Almost surely, 2^2516203981 is an apocalyptic number.

It is an amenable number.

2516203981 is a deficient number, since it is larger than the sum of its proper divisors (68005551).

2516203981 is an equidigital number, since it uses as much as digits as its factorization.

2516203981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68005550.

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 2516203981 is about 50161.7780885008. The cubic root of 2516203981 is about 1360.1347871385.

The spelling of 2516203981 in words is "two billion, five hundred sixteen million, two hundred three thousand, nine hundred eighty-one".