642878288 has 20 divisors (see below), whose sum is σ = 1341390708. Its totient is φ = 296712960.

The previous prime is 642878261. The next prime is 642878297. The reversal of 642878288 is 882878246.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 415833664 + 227044624 = 20392^2 + 15068^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1545173 + ... + 1545588.

Almost surely, 2^642878288 is an apocalyptic number.

It is an amenable number.

642878288 is an abundant number, since it is smaller than the sum of its proper divisors (698512420).

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

642878288 is a wasteful number, since it uses less digits than its factorization.

642878288 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3090782 (or 3090776 counting only the distinct ones).

The product of its digits is 2752512, while the sum is 53.

The square root of 642878288 is about 25355.0446262672. The cubic root of 642878288 is about 863.0638365495.

The spelling of 642878288 in words is "six hundred forty-two million, eight hundred seventy-eight thousand, two hundred eighty-eight".