642657461 has 4 divisors (see below), whose sum is σ = 656331072. Its totient is φ = 628983852.

The previous prime is 642657439. The next prime is 642657469. The reversal of 642657461 is 164756246.

It is a happy number.

642657461 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 a de Polignac number, because none of the positive numbers 2^k-642657461 is a prime.

It is a super-2 number, since 2×642657461² = 826017224357933042, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642657469) 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, 6836735 + ... + 6836828.

It is an arithmetic number, because the mean of its divisors is an integer number (164082768).

Almost surely, 2^642657461 is an apocalyptic number.

It is an amenable number.

642657461 is a deficient number, since it is larger than the sum of its proper divisors (13673611).

642657461 is a wasteful number, since it uses less digits than its factorization.

642657461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13673610.

The product of its digits is 241920, while the sum is 41.

The square root of 642657461 is about 25350.6895566965. The cubic root of 642657461 is about 862.9650051803.

The spelling of 642657461 in words is "six hundred forty-two million, six hundred fifty-seven thousand, four hundred sixty-one".