645122124 has 96 divisors (see below), whose sum is σ = 1837248000. Its totient is φ = 194851008.

The previous prime is 645122123. The next prime is 645122129. The reversal of 645122124 is 421221546.

645122124 is a `hidden beast` number, since 645 + 1 + 2 + 2 + 12 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (645122123) 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, 40362 + ... + 54030.

It is an arithmetic number, because the mean of its divisors is an integer number (19138000).

Almost surely, 2^645122124 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 645122124, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (918624000).

645122124 is an abundant number, since it is smaller than the sum of its proper divisors (1192125876).

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

645122124 is a wasteful number, since it uses less digits than its factorization.

645122124 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13724 (or 13716 counting only the distinct ones).

The product of its digits is 3840, while the sum is 27.

The square root of 645122124 is about 25399.2543985055. The cubic root of 645122124 is about 864.0667868897.

The spelling of 645122124 in words is "six hundred forty-five million, one hundred twenty-two thousand, one hundred twenty-four".