646612992 has 72 divisors (see below), whose sum is σ = 1867590270. Its totient is φ = 215531520.

The previous prime is 646612991. The next prime is 646613027. The reversal of 646612992 is 299216646.

It can be written as a sum of positive squares in only one way, i.e., 442008576 + 204604416 = 21024^2 + 14304^2 .

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

It is a super-2 number, since 2×646612992² = 836216722846384128, which contains 22 as substring.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (646612991) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 892 + ... + 35972.

Almost surely, 2^646612992 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 646612992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (933795135).

646612992 is an abundant number, since it is smaller than the sum of its proper divisors (1220977278).

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

646612992 is a wasteful number, since it uses less digits than its factorization.

646612992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35109 (or 35086 counting only the distinct ones).

The product of its digits is 279936, while the sum is 45.

The square root of 646612992 is about 25428.5861187759. The cubic root of 646612992 is about 864.7318901325.

The spelling of 646612992 in words is "six hundred forty-six million, six hundred twelve thousand, nine hundred ninety-two".