1639633157 has 2 divisors, whose sum is σ = 1639633158. Its totient is φ = 1639633156.

The previous prime is 1639633087. The next prime is 1639633169. The reversal of 1639633157 is 7513369361.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1639116196 + 516961 = 40486^2 + 719^2 .

It is a cyclic number.

It is not a de Polignac number, because 1639633157 - 2²⁰ = 1638584581 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1639633657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 819816578 + 819816579.

It is an arithmetic number, because the mean of its divisors is an integer number (819816579).

Almost surely, 2^1639633157 is an apocalyptic number.

It is an amenable number.

1639633157 is a deficient number, since it is larger than the sum of its proper divisors (1).

1639633157 is an equidigital number, since it uses as much as digits as its factorization.

1639633157 is an evil number, because the sum of its binary digits is even.

The product of its digits is 306180, while the sum is 44.

The square root of 1639633157 is about 40492.3839382173. The cubic root of 1639633157 is about 1179.1857729199.

The spelling of 1639633157 in words is "one billion, six hundred thirty-nine million, six hundred thirty-three thousand, one hundred fifty-seven".