157297821 has 16 divisors (see below), whose sum is σ = 223675200. Its totient is φ = 97982208.

The previous prime is 157297817. The next prime is 157297823. The reversal of 157297821 is 128792751.

It is not a de Polignac number, because 157297821 - 2² = 157297817 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (157297823) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4006 + ... + 18183.

It is an arithmetic number, because the mean of its divisors is an integer number (13979700).

Almost surely, 2^157297821 is an apocalyptic number.

It is an amenable number.

157297821 is a deficient number, since it is larger than the sum of its proper divisors (66377379).

157297821 is a wasteful number, since it uses less digits than its factorization.

157297821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22348.

The product of its digits is 70560, while the sum is 42.

The square root of 157297821 is about 12541.8428071795. The cubic root of 157297821 is about 539.8099708584.

The spelling of 157297821 in words is "one hundred fifty-seven million, two hundred ninety-seven thousand, eight hundred twenty-one".