646253520 has 160 divisors (see below), whose sum is σ = 2221893504. Its totient is φ = 154060800.

The previous prime is 646253501. The next prime is 646253527. The reversal of 646253520 is 25352646.

It is a super-2 number, since 2×646253520² = 835287224224780800, which contains 22 as substring.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646253527) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 159034 + ... + 163046.

Almost surely, 2^646253520 is an apocalyptic number.

646253520 is a gapful number since it is divisible by the number (60) 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 646253520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1110946752).

646253520 is an abundant number, since it is smaller than the sum of its proper divisors (1575639984).

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

646253520 is a wasteful number, since it uses less digits than its factorization.

646253520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4101 (or 4095 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 33.

The square root of 646253520 is about 25421.5168705567. The cubic root of 646253520 is about 864.5716167661.

The spelling of 646253520 in words is "six hundred forty-six million, two hundred fifty-three thousand, five hundred twenty".