157316721 has 8 divisors (see below), whose sum is σ = 211357344. Its totient is φ = 104076960.

The previous prime is 157316717. The next prime is 157316749. The reversal of 157316721 is 127613751.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 157316721 - 2² = 157316717 is a prime.

It is not an unprimeable number, because it can be changed into a prime (157316791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 199756 + ... + 200541.

It is an arithmetic number, because the mean of its divisors is an integer number (26419668).

Almost surely, 2^157316721 is an apocalyptic number.

It is an amenable number.

157316721 is a deficient number, since it is larger than the sum of its proper divisors (54040623).

157316721 is a wasteful number, since it uses less digits than its factorization.

157316721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 400431.

The product of its digits is 8820, while the sum is 33.

The square root of 157316721 is about 12542.5962623374. The cubic root of 157316721 is about 539.8315901446.

The spelling of 157316721 in words is "one hundred fifty-seven million, three hundred sixteen thousand, seven hundred twenty-one".