657073921 has 8 divisors (see below), whose sum is σ = 754716800. Its totient is φ = 560374848.

The previous prime is 657073897. The next prime is 657073931. The reversal of 657073921 is 129370756.

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

It is a cyclic number.

It is not a de Polignac number, because 657073921 - 2¹⁹ = 656549633 is a prime.

It is a super-2 number, since 2×657073921² = 863492275316628482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (657073931) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 234456 + ... + 237241.

It is an arithmetic number, because the mean of its divisors is an integer number (94339600).

Almost surely, 2^657073921 is an apocalyptic number.

It is an amenable number.

657073921 is a deficient number, since it is larger than the sum of its proper divisors (97642879).

657073921 is a wasteful number, since it uses less digits than its factorization.

657073921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 471903.

The product of its (nonzero) digits is 79380, while the sum is 40.

The square root of 657073921 is about 25633.4531618352. The cubic root of 657073921 is about 869.3701880297.

The spelling of 657073921 in words is "six hundred fifty-seven million, seventy-three thousand, nine hundred twenty-one".