642532644 has 36 divisors (see below), whose sum is σ = 1749117916. Its totient is φ = 197702208.

The previous prime is 642532637. The next prime is 642532651. The reversal of 642532644 is 446235246.

642532644 is a `hidden beast` number, since 6 + 4 + 2 + 5 + 3 + 2 + 644 = 666.

It is an interprime number because it is at equal distance from previous prime (642532637) and next prime (642532651).

It can be written as a sum of positive squares in 2 ways, for example, as 108368100 + 534164544 = 10410^2 + 23112^2 .

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

It is a super-3 number, since 3×642532644³ (a number of 27 digits) contains 333 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 642532599 and 642532608.

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 11 ways as a sum of consecutive naturals, for example, 685999 + ... + 686934.

Almost surely, 2^642532644 is an apocalyptic number.

It is an amenable number.

642532644 is an abundant number, since it is smaller than the sum of its proper divisors (1106585272).

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

642532644 is a wasteful number, since it uses less digits than its factorization.

642532644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1372956 (or 1372951 counting only the distinct ones).

The product of its digits is 138240, while the sum is 36.

The square root of 642532644 is about 25348.2276303492. The cubic root of 642532644 is about 862.9091331782.

The spelling of 642532644 in words is "six hundred forty-two million, five hundred thirty-two thousand, six hundred forty-four".