645424416 has 192 divisors, whose sum is σ = 2317190400. Its totient is φ = 170201088.

The previous prime is 645424393. The next prime is 645424427. The reversal of 645424416 is 614424546.

645424416 is a `hidden beast` number, since 64 + 542 + 44 + 16 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 74520 + ... + 82728.

It is an arithmetic number, because the mean of its divisors is an integer number (12068700).

Almost surely, 2^645424416 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 645424416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1158595200).

645424416 is an abundant number, since it is smaller than the sum of its proper divisors (1671765984).

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

645424416 is a wasteful number, since it uses less digits than its factorization.

645424416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8248 (or 8234 counting only the distinct ones).

The product of its digits is 92160, while the sum is 36.

The square root of 645424416 is about 25405.2045061637. The cubic root of 645424416 is about 864.2017275881.

The spelling of 645424416 in words is "six hundred forty-five million, four hundred twenty-four thousand, four hundred sixteen".