642985944 has 64 divisors (see below), whose sum is σ = 1681827840. Its totient is φ = 204637440.

The previous prime is 642985939. The next prime is 642985949. The reversal of 642985944 is 449589246.

It is an interprime number because it is at equal distance from previous prime (642985939) and next prime (642985949).

It is a super-2 number, since 2×642985944² = 826861848363142272, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642985949) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39297 + ... + 53199.

It is an arithmetic number, because the mean of its divisors is an integer number (26278560).

Almost surely, 2^642985944 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 642985944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (840913920).

642985944 is an abundant number, since it is smaller than the sum of its proper divisors (1038841896).

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

642985944 is a wasteful number, since it uses less digits than its factorization.

642985944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14000 (or 13996 counting only the distinct ones).

The product of its digits is 2488320, while the sum is 51.

The square root of 642985944 is about 25357.1675074327. The cubic root of 642985944 is about 863.1120099057.

The spelling of 642985944 in words is "six hundred forty-two million, nine hundred eighty-five thousand, nine hundred forty-four".