2521944236981 has 4 divisors (see below), whose sum is σ = 2715939947532. Its totient is φ = 2327948526432.

The previous prime is 2521944236957. The next prime is 2521944237013. The reversal of 2521944236981 is 1896324491252.

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 415283580625 + 2106660656356 = 644425^2 + 1451434^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2521944236981 is a prime.

It is a super-2 number, since 2×2521944236981² (a number of 26 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2521944236951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 96997855256 + ... + 96997855281.

It is an arithmetic number, because the mean of its divisors is an integer number (678984986883).

Almost surely, 2^{2521944236981} is an apocalyptic number.

It is an amenable number.

2521944236981 is a deficient number, since it is larger than the sum of its proper divisors (193995710551).

2521944236981 is a wasteful number, since it uses less digits than its factorization.

2521944236981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 193995710550.

The product of its digits is 7464960, while the sum is 56.

The spelling of 2521944236981 in words is "two trillion, five hundred twenty-one billion, nine hundred forty-four million, two hundred thirty-six thousand, nine hundred eighty-one".