157901561 has 2 divisors, whose sum is σ = 157901562. Its totient is φ = 157901560.

The previous prime is 157901551. The next prime is 157901563. The reversal of 157901561 is 165109751.

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., 125865961 + 32035600 = 11219^2 + 5660^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-157901561 is a prime.

Together with 157901563, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (157901563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78950780 + 78950781.

It is an arithmetic number, because the mean of its divisors is an integer number (78950781).

Almost surely, 2^157901561 is an apocalyptic number.

It is an amenable number.

157901561 is a deficient number, since it is larger than the sum of its proper divisors (1).

157901561 is an equidigital number, since it uses as much as digits as its factorization.

157901561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9450, while the sum is 35.

The square root of 157901561 is about 12565.8887867114. Note that the first 3 decimals coincide. The cubic root of 157901561 is about 540.4997214521.

The spelling of 157901561 in words is "one hundred fifty-seven million, nine hundred one thousand, five hundred sixty-one".