2051918987 has 4 divisors (see below), whose sum is σ = 2141132880. Its totient is φ = 1962705096.

The previous prime is 2051918971. The next prime is 2051918993. The reversal of 2051918987 is 7898191502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7898191502 = 2 ⋅3949095751.

It is a cyclic number.

It is not a de Polignac number, because 2051918987 - 2⁴ = 2051918971 is a prime.

It is a super-2 number, since 2×2051918987² = 8420743058422212338, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2051918087) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44606912 + ... + 44606957.

It is an arithmetic number, because the mean of its divisors is an integer number (535283220).

Almost surely, 2^2051918987 is an apocalyptic number.

2051918987 is a deficient number, since it is larger than the sum of its proper divisors (89213893).

2051918987 is an equidigital number, since it uses as much as digits as its factorization.

2051918987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89213892.

The product of its (nonzero) digits is 362880, while the sum is 50.

The square root of 2051918987 is about 45298.1123999665. The cubic root of 2051918987 is about 1270.7303520166.

The spelling of 2051918987 in words is "two billion, fifty-one million, nine hundred eighteen thousand, nine hundred eighty-seven".