642165888 has 512 divisors, whose sum is σ = 2368880640. Its totient is φ = 149225472.

The previous prime is 642165863. The next prime is 642165893. The reversal of 642165888 is 888561246.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 13663081 + ... + 13663127.

It is an arithmetic number, because the mean of its divisors is an integer number (4626720).

Almost surely, 2^642165888 is an apocalyptic number.

642165888 is a gapful number since it is divisible by the number (68) 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 642165888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1184440320).

642165888 is an abundant number, since it is smaller than the sum of its proper divisors (1726714752).

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

642165888 is a wasteful number, since it uses less digits than its factorization.

642165888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124 (or 112 counting only the distinct ones).

The product of its digits is 737280, while the sum is 48.

The square root of 642165888 is about 25340.9922457665. The cubic root of 642165888 is about 862.7449198167.

The spelling of 642165888 in words is "six hundred forty-two million, one hundred sixty-five thousand, eight hundred eighty-eight".