157928681 has 2 divisors, whose sum is σ = 157928682. Its totient is φ = 157928680.

The previous prime is 157928671. The next prime is 157928699. The reversal of 157928681 is 186829751.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 144120025 + 13808656 = 12005^2 + 3716^2 .

It is an emirp because it is prime and its reverse (186829751) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-157928681 is a prime.

It is a super-2 number, since 2×157928681² = 49882936564799522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (157928611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78964340 + 78964341.

It is an arithmetic number, because the mean of its divisors is an integer number (78964341).

Almost surely, 2^157928681 is an apocalyptic number.

It is an amenable number.

157928681 is a deficient number, since it is larger than the sum of its proper divisors (1).

157928681 is an equidigital number, since it uses as much as digits as its factorization.

157928681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 241920, while the sum is 47.

The square root of 157928681 is about 12566.9678522705. The cubic root of 157928681 is about 540.5306637541.

The spelling of 157928681 in words is "one hundred fifty-seven million, nine hundred twenty-eight thousand, six hundred eighty-one".