2151356881 has 4 divisors (see below), whose sum is σ = 2151544500. Its totient is φ = 2151169264.

The previous prime is 2151356849. The next prime is 2151356887. The reversal of 2151356881 is 1886531512.

It is a happy number.

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 2084379025 + 66977856 = 45655^2 + 8184^2 .

It is a cyclic number.

It is not a de Polignac number, because 2151356881 - 2⁵ = 2151356849 is a prime.

It is a super-2 number, since 2×2151356881² = 9256672858852096322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2151356887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 75406 + ... + 99943.

It is an arithmetic number, because the mean of its divisors is an integer number (537886125).

Almost surely, 2^2151356881 is an apocalyptic number.

It is an amenable number.

2151356881 is a deficient number, since it is larger than the sum of its proper divisors (187619).

2151356881 is a wasteful number, since it uses less digits than its factorization.

2151356881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187618.

The product of its digits is 57600, while the sum is 40.

The square root of 2151356881 is about 46382.7217937887. The cubic root of 2151356881 is about 1290.9343392252.

The spelling of 2151356881 in words is "two billion, one hundred fifty-one million, three hundred fifty-six thousand, eight hundred eighty-one".