2152797981 has 4 divisors (see below), whose sum is σ = 2870397312. Its totient is φ = 1435198652.

The previous prime is 2152797979. The next prime is 2152797989. The reversal of 2152797981 is 1897972512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2152797981 - 2¹ = 2152797979 is a prime.

It is a super-2 number, since 2×2152797981² = 9269078293995352722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2152797989) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 358799661 + ... + 358799666.

It is an arithmetic number, because the mean of its divisors is an integer number (717599328).

Almost surely, 2^2152797981 is an apocalyptic number.

It is an amenable number.

2152797981 is a deficient number, since it is larger than the sum of its proper divisors (717599331).

2152797981 is an equidigital number, since it uses as much as digits as its factorization.

2152797981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 717599330.

The product of its digits is 635040, while the sum is 51.

The square root of 2152797981 is about 46398.2540727558. The cubic root of 2152797981 is about 1291.2225217291. Note that the first 3 decimals are identical.

The spelling of 2152797981 in words is "two billion, one hundred fifty-two million, seven hundred ninety-seven thousand, nine hundred eighty-one".