157690381 has 2 divisors, whose sum is σ = 157690382. Its totient is φ = 157690380.

The previous prime is 157690319. The next prime is 157690433. The reversal of 157690381 is 183096751.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 156500100 + 1190281 = 12510^2 + 1091^2 .

It is an emirp because it is prime and its reverse (183096751) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 157690381 - 2¹⁵ = 157657613 is a prime.

It is a super-2 number, since 2×157690381² = 49732512519850322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (157690681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78845190 + 78845191.

It is an arithmetic number, because the mean of its divisors is an integer number (78845191).

Almost surely, 2^157690381 is an apocalyptic number.

It is an amenable number.

157690381 is a deficient number, since it is larger than the sum of its proper divisors (1).

157690381 is an equidigital number, since it uses as much as digits as its factorization.

157690381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 45360, while the sum is 40.

The square root of 157690381 is about 12557.4830678763. The cubic root of 157690381 is about 540.2586563782.

The spelling of 157690381 in words is "one hundred fifty-seven million, six hundred ninety thousand, three hundred eighty-one".