157720513 has 2 divisors, whose sum is σ = 157720514. Its totient is φ = 157720512.

The previous prime is 157720483. The next prime is 157720561. The reversal of 157720513 is 315027751.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 155550784 + 2169729 = 12472^2 + 1473^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-157720513 is a prime.

It is not a weakly prime, because it can be changed into another prime (157720573) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78860256 + 78860257.

It is an arithmetic number, because the mean of its divisors is an integer number (78860257).

Almost surely, 2^157720513 is an apocalyptic number.

It is an amenable number.

157720513 is a deficient number, since it is larger than the sum of its proper divisors (1).

157720513 is an equidigital number, since it uses as much as digits as its factorization.

157720513 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7350, while the sum is 31.

The square root of 157720513 is about 12558.6827732848. The cubic root of 157720513 is about 540.2930656574.

The spelling of 157720513 in words is "one hundred fifty-seven million, seven hundred twenty thousand, five hundred thirteen".