642534816 has 96 divisors (see below), whose sum is σ = 2102865408. Its totient is φ = 166890240.

The previous prime is 642534811. The next prime is 642534869. The reversal of 642534816 is 618435246.

It is a tau number, because it is divible by the number of its divisors (96).

It is not an unprimeable number, because it can be changed into a prime (642534811) 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, 36070 + ... + 50853.

It is an arithmetic number, because the mean of its divisors is an integer number (21904848).

Almost surely, 2^642534816 is an apocalyptic number.

642534816 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

642534816 is an abundant number, since it is smaller than the sum of its proper divisors (1460330592).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

642534816 is a wasteful number, since it uses less digits than its factorization.

642534816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86954 (or 86946 counting only the distinct ones).

The product of its digits is 138240, while the sum is 39.

The square root of 642534816 is about 25348.2704735451. The cubic root of 642534816 is about 862.9101054953.

The spelling of 642534816 in words is "six hundred forty-two million, five hundred thirty-four thousand, eight hundred sixteen".