642165660 has 36 divisors (see below), whose sum is σ = 1947903048. Its totient is φ = 171244128.

The previous prime is 642165659. The next prime is 642165661. The reversal of 642165660 is 66561246.

It is a happy number.

642165660 is a `hidden beast` number, since 642 + 1 + 6 + 5 + 6 + 6 + 0 = 666.

642165660 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (642165659) and next prime (642165661).

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642165661) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1783614 + ... + 1783973.

It is an arithmetic number, because the mean of its divisors is an integer number (54108418).

Almost surely, 2^642165660 is an apocalyptic number.

642165660 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

642165660 is an abundant number, since it is smaller than the sum of its proper divisors (1305737388).

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

642165660 is a wasteful number, since it uses less digits than its factorization.

642165660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3567602 (or 3567597 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 642165660 is about 25340.9877471262. The cubic root of 642165660 is about 862.7448177113.

The spelling of 642165660 in words is "six hundred forty-two million, one hundred sixty-five thousand, six hundred sixty".