2151930997 has 4 divisors (see below), whose sum is σ = 2152202656. Its totient is φ = 2151659340.

The previous prime is 2151930959. The next prime is 2151931021. The reversal of 2151930997 is 7990391512.

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 2151930997 - 2¹⁹ = 2151406709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2151930497) 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, 123579 + ... + 139912.

It is an arithmetic number, because the mean of its divisors is an integer number (538050664).

Almost surely, 2^2151930997 is an apocalyptic number.

It is an amenable number.

2151930997 is a deficient number, since it is larger than the sum of its proper divisors (271659).

2151930997 is an equidigital number, since it uses as much as digits as its factorization.

2151930997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 271658.

The product of its (nonzero) digits is 153090, while the sum is 46.

The square root of 2151930997 is about 46388.9102803677. The cubic root of 2151930997 is about 1291.0491629050.

The spelling of 2151930997 in words is "two billion, one hundred fifty-one million, nine hundred thirty thousand, nine hundred ninety-seven".