645242544 has 40 divisors (see below), whose sum is σ = 1852086320. Its totient is φ = 215080704.

The previous prime is 645242539. The next prime is 645242557. The reversal of 645242544 is 445242546.

645242544 is a `hidden beast` number, since 64 + 52 + 4 + 2 + 544 = 666.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

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

It is a junction number, because it is equal to n+sod(n) for n = 645242499 and 645242508.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 746377 + ... + 747240.

It is an arithmetic number, because the mean of its divisors is an integer number (46302158).

Almost surely, 2^645242544 is an apocalyptic number.

It is an amenable number.

645242544 is an abundant number, since it is smaller than the sum of its proper divisors (1206843776).

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

645242544 is a wasteful number, since it uses less digits than its factorization.

645242544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1493634 (or 1493622 counting only the distinct ones).

The product of its digits is 153600, while the sum is 36.

The square root of 645242544 is about 25401.6248299198. The cubic root of 645242544 is about 864.1205464520.

The spelling of 645242544 in words is "six hundred forty-five million, two hundred forty-two thousand, five hundred forty-four".