646297920 has 448 divisors, whose sum is σ = 2496921600. Its totient is φ = 156764160.

The previous prime is 646297919. The next prime is 646297921. The reversal of 646297920 is 29792646.

It is an interprime number because it is at equal distance from previous prime (646297919) and next prime (646297921).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646297921) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5088897 + ... + 5089023.

Almost surely, 2^646297920 is an apocalyptic number.

646297920 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 646297920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1248460800).

646297920 is an abundant number, since it is smaller than the sum of its proper divisors (1850623680).

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

646297920 is a wasteful number, since it uses less digits than its factorization.

646297920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203 (or 187 counting only the distinct ones).

The product of its (nonzero) digits is 326592, while the sum is 45.

The square root of 646297920 is about 25422.3901315356. The cubic root of 646297920 is about 864.5914160655.

The spelling of 646297920 in words is "six hundred forty-six million, two hundred ninety-seven thousand, nine hundred twenty".