645166144 has 84 divisors (see below), whose sum is σ = 1495866960. Its totient is φ = 275278080.

The previous prime is 645166139. The next prime is 645166157. The reversal of 645166144 is 441661546.

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1313739 + ... + 1314229.

It is an arithmetic number, because the mean of its divisors is an integer number (17807940).

Almost surely, 2^645166144 is an apocalyptic number.

645166144 is a gapful number since it is divisible by the number (64) 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 645166144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (747933480).

645166144 is an abundant number, since it is smaller than the sum of its proper divisors (850700816).

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

645166144 is a wasteful number, since it uses less digits than its factorization.

645166144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 936 (or 919 counting only the distinct ones).

The product of its digits is 69120, while the sum is 37.

The square root of 645166144 is about 25400.1209445939. The cubic root of 645166144 is about 864.0864396828.

The spelling of 645166144 in words is "six hundred forty-five million, one hundred sixty-six thousand, one hundred forty-four".