1657397901 has 4 divisors (see below), whose sum is σ = 2209863872. Its totient is φ = 1104931932.

The previous prime is 1657397897. The next prime is 1657397921. The reversal of 1657397901 is 1097937561.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1657397901 - 2² = 1657397897 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1657397921) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 276232981 + ... + 276232986.

It is an arithmetic number, because the mean of its divisors is an integer number (552465968).

Almost surely, 2^1657397901 is an apocalyptic number.

It is an amenable number.

1657397901 is a deficient number, since it is larger than the sum of its proper divisors (552465971).

1657397901 is an equidigital number, since it uses as much as digits as its factorization.

1657397901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 552465970.

The product of its (nonzero) digits is 357210, while the sum is 48.

The square root of 1657397901 is about 40711.1520470743. The cubic root of 1657397901 is about 1183.4291471890.

The spelling of 1657397901 in words is "one billion, six hundred fifty-seven million, three hundred ninety-seven thousand, nine hundred one".