642017620 has 48 divisors (see below), whose sum is σ = 1384015248. Its totient is φ = 250065920.

The previous prime is 642017617. The next prime is 642017627. The reversal of 642017620 is 26710246.

It can be written as a sum of positive squares in 8 ways, for example, as 44997264 + 597020356 = 6708^2 + 24434^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642017627) 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, 143010 + ... + 147430.

It is an arithmetic number, because the mean of its divisors is an integer number (28833651).

Almost surely, 2^642017620 is an apocalyptic number.

It is an amenable number.

642017620 is an abundant number, since it is smaller than the sum of its proper divisors (741997628).

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

642017620 is a wasteful number, since it uses less digits than its factorization.

642017620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4620 (or 4618 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 642017620 is about 25338.0666192194. The cubic root of 642017620 is about 862.6785157342.

Adding to 642017620 its reverse (26710246), we get a palindrome (668727866).

The spelling of 642017620 in words is "six hundred forty-two million, seventeen thousand, six hundred twenty".