642133890 has 48 divisors (see below), whose sum is σ = 1714679928. Its totient is φ = 166606848.

The previous prime is 642133859. The next prime is 642133909. The reversal of 642133890 is 98331246.

642133890 is a `hidden beast` number, since 64 + 213 + 389 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 424895769 + 217238121 = 20613^2 + 14739^2 .

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, 93087 + ... + 99746.

Almost surely, 2^642133890 is an apocalyptic number.

642133890 is an abundant number, since it is smaller than the sum of its proper divisors (1072546038).

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

642133890 is a wasteful number, since it uses less digits than its factorization.

642133890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 192883 (or 192880 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 642133890 is about 25340.3608893007. The cubic root of 642133890 is about 862.7305898900.

The spelling of 642133890 in words is "six hundred forty-two million, one hundred thirty-three thousand, eight hundred ninety".