642211900 has 72 divisors (see below), whose sum is σ = 1526402304. Its totient is φ = 232593600.

The previous prime is 642211897. The next prime is 642211943. The reversal of 642211900 is 9112246.

It is a super-2 number, since 2×642211900² = 824872249003220000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 310269 + ... + 312331.

It is an arithmetic number, because the mean of its divisors is an integer number (21200032).

Almost surely, 2^642211900 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 642211900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (763201152).

642211900 is an abundant number, since it is smaller than the sum of its proper divisors (884190404).

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

642211900 is a wasteful number, since it uses less digits than its factorization.

642211900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2371 (or 2364 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 642211900 is about 25341.9000866154. The cubic root of 642211900 is about 862.7655249137.

The spelling of 642211900 in words is "six hundred forty-two million, two hundred eleven thousand, nine hundred".