642126499021 has 24 divisors (see below), whose sum is σ = 755283992064. Its totient is φ = 544295959200.

The previous prime is 642126498977. The next prime is 642126499043. The reversal of 642126499021 is 120994621246.

It is a happy number.

It is not a de Polignac number, because 642126499021 - 2¹⁹ = 642125974733 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642126499081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1455391 + ... + 1844563.

It is an arithmetic number, because the mean of its divisors is an integer number (31470166336).

Almost surely, 2^642126499021 is an apocalyptic number.

It is an amenable number.

642126499021 is a deficient number, since it is larger than the sum of its proper divisors (113157493043).

642126499021 is a wasteful number, since it uses less digits than its factorization.

642126499021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 389561 (or 389554 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 46.

The spelling of 642126499021 in words is "six hundred forty-two billion, one hundred twenty-six million, four hundred ninety-nine thousand, twenty-one".