657242381 has 4 divisors (see below), whose sum is σ = 658560000. Its totient is φ = 655924764.

The previous prime is 657242371. The next prime is 657242413. The reversal of 657242381 is 183242756.

It is a happy number.

657242381 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 a cyclic number.

It is not a de Polignac number, because 657242381 - 2¹⁸ = 656980237 is a prime.

It is a super-2 number, since 2×657242381² = 863935094765098322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (657242371) 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, 658061 + ... + 659058.

It is an arithmetic number, because the mean of its divisors is an integer number (164640000).

Almost surely, 2^657242381 is an apocalyptic number.

It is an amenable number.

657242381 is a deficient number, since it is larger than the sum of its proper divisors (1317619).

657242381 is a wasteful number, since it uses less digits than its factorization.

657242381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1317618.

The product of its digits is 80640, while the sum is 38.

The square root of 657242381 is about 25636.7388916765. The cubic root of 657242381 is about 869.4444777877. Note that the first 4 decimals are identical.

The spelling of 657242381 in words is "six hundred fifty-seven million, two hundred forty-two thousand, three hundred eighty-one".