2156520249 has 12 divisors (see below), whose sum is σ = 3354587236. Its totient is φ = 1327089312.

The previous prime is 2156520211. The next prime is 2156520271. The reversal of 2156520249 is 9420256512.

It can be written as a sum of positive squares in 2 ways, for example, as 1374926400 + 781593849 = 37080^2 + 27957^2 .

It is not a de Polignac number, because 2156520249 - 2²¹ = 2154423097 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2156520049) 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 11 ways as a sum of consecutive naturals, for example, 9215782 + ... + 9216015.

Almost surely, 2^2156520249 is an apocalyptic number.

It is an amenable number.

2156520249 is a deficient number, since it is larger than the sum of its proper divisors (1198066987).

2156520249 is a wasteful number, since it uses less digits than its factorization.

2156520249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18431816 (or 18431813 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The square root of 2156520249 is about 46438.3489047576. The cubic root of 2156520249 is about 1291.9662838620.

It can be divided in two parts, 21565 and 20249, that added together give a palindrome (41814).

The spelling of 2156520249 in words is "two billion, one hundred fifty-six million, five hundred twenty thousand, two hundred forty-nine".