157639961 has 2 divisors, whose sum is σ = 157639962. Its totient is φ = 157639960.

The previous prime is 157639949. The next prime is 157639987. The reversal of 157639961 is 169936751.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 121110025 + 36529936 = 11005^2 + 6044^2 .

It is a cyclic number.

It is not a de Polignac number, because 157639961 - 2⁶ = 157639897 is a prime.

It is a super-3 number, since 3×157639961³ (a number of 26 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (157639931) 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 as a sum of consecutive naturals, namely, 78819980 + 78819981.

It is an arithmetic number, because the mean of its divisors is an integer number (78819981).

Almost surely, 2^157639961 is an apocalyptic number.

It is an amenable number.

157639961 is a deficient number, since it is larger than the sum of its proper divisors (1).

157639961 is an equidigital number, since it uses as much as digits as its factorization.

157639961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 306180, while the sum is 47.

The square root of 157639961 is about 12555.4753394684. The cubic root of 157639961 is about 540.2010693839.

The spelling of 157639961 in words is "one hundred fifty-seven million, six hundred thirty-nine thousand, nine hundred sixty-one".