642120995761 has 16 divisors (see below), whose sum is σ = 754263688320. Its totient is φ = 535283844480.

The previous prime is 642120995627. The next prime is 642120995783. The reversal of 642120995761 is 167599021246.

It is not a de Polignac number, because 642120995761 - 2³⁹ = 92365181873 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 642120995699 and 642120995708.

It is not an unprimeable number, because it can be changed into a prime (642120995261) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8410291 + ... + 8486296.

It is an arithmetic number, because the mean of its divisors is an integer number (47141480520).

Almost surely, 2^642120995761 is an apocalyptic number.

642120995761 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

It is an amenable number.

642120995761 is a deficient number, since it is larger than the sum of its proper divisors (112142692559).

642120995761 is a wasteful number, since it uses less digits than its factorization.

642120995761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16896744.

The product of its (nonzero) digits is 1632960, while the sum is 52.

The spelling of 642120995761 in words is "six hundred forty-two billion, one hundred twenty million, nine hundred ninety-five thousand, seven hundred sixty-one".