642188490 has 32 divisors (see below), whose sum is σ = 1546836480. Its totient is φ = 170629824.

The previous prime is 642188483. The next prime is 642188537. The reversal of 642188490 is 94881246.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30330 + ... + 46949.

It is an arithmetic number, because the mean of its divisors is an integer number (48338640).

Almost surely, 2^642188490 is an apocalyptic number.

642188490 is an abundant number, since it is smaller than the sum of its proper divisors (904647990).

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

642188490 is a wasteful number, since it uses less digits than its factorization.

642188490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77566.

The product of its (nonzero) digits is 110592, while the sum is 42.

The square root of 642188490 is about 25341.4381991236. The cubic root of 642188490 is about 862.7550415689.

The spelling of 642188490 in words is "six hundred forty-two million, one hundred eighty-eight thousand, four hundred ninety".