642541644 has 36 divisors (see below), whose sum is σ = 1624972440. Its totient is φ = 214079040.

The previous prime is 642541643. The next prime is 642541649. The reversal of 642541644 is 446145246.

642541644 is a `hidden beast` number, since 6 + 4 + 2 + 5 + 4 + 1 + 644 = 666.

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 junction number, because it is equal to n+sod(n) for n = 642541599 and 642541608.

It is not an unprimeable number, because it can be changed into a prime (642541643) 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, 142464 + ... + 146904.

Almost surely, 2^642541644 is an apocalyptic number.

It is an amenable number.

642541644 is an abundant number, since it is smaller than the sum of its proper divisors (982430796).

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

642541644 is a wasteful number, since it uses less digits than its factorization.

642541644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8470 (or 8465 counting only the distinct ones).

The product of its digits is 92160, while the sum is 36.

The square root of 642541644 is about 25348.4051569325. The cubic root of 642541644 is about 862.9131621024.

The spelling of 642541644 in words is "six hundred forty-two million, five hundred forty-one thousand, six hundred forty-four".