642549404 has 24 divisors (see below), whose sum is σ = 1329414240. Its totient is φ = 265882176.

The previous prime is 642549389. The next prime is 642549407. The reversal of 642549404 is 404945246.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642549407) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 394847 + ... + 396470.

It is an arithmetic number, because the mean of its divisors is an integer number (55392260).

Almost surely, 2^642549404 is an apocalyptic number.

It is an amenable number.

642549404 is an abundant number, since it is smaller than the sum of its proper divisors (686864836).

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

642549404 is a wasteful number, since it uses less digits than its factorization.

642549404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 791357 (or 791355 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 38.

The square root of 642549404 is about 25348.5582232994. The cubic root of 642549404 is about 862.9166359001.

The spelling of 642549404 in words is "six hundred forty-two million, five hundred forty-nine thousand, four hundred four".