642096421 has 4 divisors (see below), whose sum is σ = 645139744. Its totient is φ = 639053100.

The previous prime is 642096419. The next prime is 642096457. The reversal of 642096421 is 124690246.

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 642096421 - 2¹ = 642096419 is a prime.

It is a super-2 number, since 2×642096421² = 824575627722018482, 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 (642096821) 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, 1521345 + ... + 1521766.

It is an arithmetic number, because the mean of its divisors is an integer number (161284936).

Almost surely, 2^642096421 is an apocalyptic number.

It is an amenable number.

642096421 is a deficient number, since it is larger than the sum of its proper divisors (3043323).

642096421 is a wasteful number, since it uses less digits than its factorization.

642096421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3043322.

The product of its (nonzero) digits is 20736, while the sum is 34.

The square root of 642096421 is about 25339.6215638671. The cubic root of 642096421 is about 862.7138092353.

The spelling of 642096421 in words is "six hundred forty-two million, ninety-six thousand, four hundred twenty-one".