2151725657 has 2 divisors, whose sum is σ = 2151725658. Its totient is φ = 2151725656.

The previous prime is 2151725629. The next prime is 2151725669. The reversal of 2151725657 is 7565271512.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1223670361 + 928055296 = 34981^2 + 30464^2 .

It is a cyclic number.

It is not a de Polignac number, because 2151725657 - 2²⁴ = 2134948441 is a prime.

It is not a weakly prime, because it can be changed into another prime (2151725617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1075862828 + 1075862829.

It is an arithmetic number, because the mean of its divisors is an integer number (1075862829).

Almost surely, 2^2151725657 is an apocalyptic number.

It is an amenable number.

2151725657 is a deficient number, since it is larger than the sum of its proper divisors (1).

2151725657 is an equidigital number, since it uses as much as digits as its factorization.

2151725657 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 147000, while the sum is 41.

The square root of 2151725657 is about 46386.6969830791. The cubic root of 2151725657 is about 1291.0080970796.

It can be divided in two parts, 21517 and 25657, that added together give a palindrome (47174).

The spelling of 2151725657 in words is "two billion, one hundred fifty-one million, seven hundred twenty-five thousand, six hundred fifty-seven".