657901421 has 2 divisors, whose sum is σ = 657901422. Its totient is φ = 657901420.

The previous prime is 657901417. The next prime is 657901459. The reversal of 657901421 is 124109756.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 654643396 + 3258025 = 25586^2 + 1805^2 .

It is a cyclic number.

It is not a de Polignac number, because 657901421 - 2² = 657901417 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (657901471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328950710 + 328950711.

It is an arithmetic number, because the mean of its divisors is an integer number (328950711).

Almost surely, 2^657901421 is an apocalyptic number.

It is an amenable number.

657901421 is a deficient number, since it is larger than the sum of its proper divisors (1).

657901421 is an equidigital number, since it uses as much as digits as its factorization.

657901421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 657901421 is about 25649.5891000226. The cubic root of 657901421 is about 869.7349882041.

The spelling of 657901421 in words is "six hundred fifty-seven million, nine hundred one thousand, four hundred twenty-one".