646663472 has 80 divisors (see below), whose sum is σ = 1591898112. Its totient is φ = 247553280.

The previous prime is 646663453. The next prime is 646663483. The reversal of 646663472 is 274366646.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37973 + ... + 52299.

Almost surely, 2^646663472 is an apocalyptic number.

646663472 is a gapful number since it is divisible by the number (62) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 646663472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (795949056).

646663472 is an abundant number, since it is smaller than the sum of its proper divisors (945234640).

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

646663472 is a wasteful number, since it uses less digits than its factorization.

646663472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14386 (or 14380 counting only the distinct ones).

The product of its digits is 870912, while the sum is 44.

The square root of 646663472 is about 25429.5786831005. The cubic root of 646663472 is about 864.7543922734.

The spelling of 646663472 in words is "six hundred forty-six million, six hundred sixty-three thousand, four hundred seventy-two".