642990000 has 100 divisors (see below), whose sum is σ = 2075754296. Its totient is φ = 171456000.

The previous prime is 642989999. The next prime is 642990013. The reversal of 642990000 is 99246.

It is a tau number, because it is divible by the number of its divisors (100).

It is a super-2 number, since 2×642990000² = 826872280200000000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a self number, because there is not a number n which added to its sum of digits gives 642990000.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 19284 + ... + 40716.

Almost surely, 2^642990000 is an apocalyptic number.

642990000 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 642990000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1037877148).

642990000 is an abundant number, since it is smaller than the sum of its proper divisors (1432764296).

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

642990000 is a wasteful number, since it uses less digits than its factorization.

642990000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21464 (or 21443 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 30.

The square root of 642990000 is about 25357.2474846936. The cubic root of 642990000 is about 863.1138247587.

The spelling of 642990000 in words is "six hundred forty-two million, nine hundred ninety thousand".