157858721 has 2 divisors, whose sum is σ = 157858722. Its totient is φ = 157858720.

The previous prime is 157858681. The next prime is 157858741. The reversal of 157858721 is 127858751.

157858721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 149793121 + 8065600 = 12239^2 + 2840^2 .

It is a cyclic number.

It is not a de Polignac number, because 157858721 - 2¹⁸ = 157596577 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (157858741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78929360 + 78929361.

It is an arithmetic number, because the mean of its divisors is an integer number (78929361).

Almost surely, 2^157858721 is an apocalyptic number.

It is an amenable number.

157858721 is a deficient number, since it is larger than the sum of its proper divisors (1).

157858721 is an equidigital number, since it uses as much as digits as its factorization.

157858721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 156800, while the sum is 44.

The square root of 157858721 is about 12564.1840562768. The cubic root of 157858721 is about 540.4508363487.

The spelling of 157858721 in words is "one hundred fifty-seven million, eight hundred fifty-eight thousand, seven hundred twenty-one".