2156520251 has 16 divisors (see below), whose sum is σ = 2212923840. Its totient is φ = 2100919680.

The previous prime is 2156520211. The next prime is 2156520271. The reversal of 2156520251 is 1520256512.

It is a cyclic number.

It is not a de Polignac number, because 2156520251 - 2¹⁸ = 2156258107 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2156520211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4427930 + ... + 4428416.

It is an arithmetic number, because the mean of its divisors is an integer number (138307740).

Almost surely, 2^2156520251 is an apocalyptic number.

2156520251 is a deficient number, since it is larger than the sum of its proper divisors (56403589).

2156520251 is a wasteful number, since it uses less digits than its factorization.

2156520251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1094.

The product of its (nonzero) digits is 6000, while the sum is 29.

The square root of 2156520251 is about 46438.3489262915. The cubic root of 2156520251 is about 1291.9662842614.

Adding to 2156520251 its reverse (1520256512), we get a palindrome (3676776763).

The spelling of 2156520251 in words is "two billion, one hundred fifty-six million, five hundred twenty thousand, two hundred fifty-one".