157720897 has 2 divisors, whose sum is σ = 157720898. Its totient is φ = 157720896.

The previous prime is 157720873. The next prime is 157720903. The reversal of 157720897 is 798027751.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 114896961 + 42823936 = 10719^2 + 6544^2 .

It is a cyclic number.

It is not a de Polignac number, because 157720897 - 2⁷ = 157720769 is a prime.

It is not a weakly prime, because it can be changed into another prime (157720097) 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, 78860448 + 78860449.

It is an arithmetic number, because the mean of its divisors is an integer number (78860449).

Almost surely, 2^157720897 is an apocalyptic number.

It is an amenable number.

157720897 is a deficient number, since it is larger than the sum of its proper divisors (1).

157720897 is an equidigital number, since it uses as much as digits as its factorization.

157720897 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 246960, while the sum is 46.

The square root of 157720897 is about 12558.6980615030. The cubic root of 157720897 is about 540.2935041385.

The spelling of 157720897 in words is "one hundred fifty-seven million, seven hundred twenty thousand, eight hundred ninety-seven".