642783456 has 72 divisors (see below), whose sum is σ = 2089052784. Its totient is φ = 183651840.

The previous prime is 642783443. The next prime is 642783473. The reversal of 642783456 is 654387246.

It is a tau number, because it is divible by the number of its divisors (72).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 157405 + ... + 161436.

It is an arithmetic number, because the mean of its divisors is an integer number (29014622).

Almost surely, 2^642783456 is an apocalyptic number.

It is an amenable number.

642783456 is an abundant number, since it is smaller than the sum of its proper divisors (1446269328).

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

642783456 is a wasteful number, since it uses less digits than its factorization.

642783456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 318864 (or 318853 counting only the distinct ones).

The product of its digits is 967680, while the sum is 45.

The square root of 642783456 is about 25353.1744757930. The cubic root of 642783456 is about 863.0213971556.

The spelling of 642783456 in words is "six hundred forty-two million, seven hundred eighty-three thousand, four hundred fifty-six".