642244656 has 40 divisors (see below), whose sum is σ = 1681869040. Its totient is φ = 211147776.

The previous prime is 642244651. The next prime is 642244667. The reversal of 642244656 is 656442246.

642244656 = T₄₀₉ + T₄₁₀ + ... + T₁₅₇₆.

It is not an unprimeable number, because it can be changed into a prime (642244651) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 88141 + ... + 95148.

It is an arithmetic number, because the mean of its divisors is an integer number (42046726).

Almost surely, 2^642244656 is an apocalyptic number.

It is an amenable number.

642244656 is an abundant number, since it is smaller than the sum of its proper divisors (1039624384).

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

642244656 is a wasteful number, since it uses less digits than its factorization.

642244656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 183373 (or 183367 counting only the distinct ones).

The product of its digits is 276480, while the sum is 39.

The square root of 642244656 is about 25342.5463598274. The cubic root of 642244656 is about 862.7801931082.

The spelling of 642244656 in words is "six hundred forty-two million, two hundred forty-four thousand, six hundred fifty-six".