645742524 has 192 divisors, whose sum is σ = 1867120640. Its totient is φ = 169827840.

The previous prime is 645742511. The next prime is 645742529. The reversal of 645742524 is 425247546.

Its product of digits (268800) is a multiple of the sum of its prime factors (240).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645742529) 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, 8173917 + ... + 8173995.

Almost surely, 2^645742524 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 645742524, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (933560320).

645742524 is an abundant number, since it is smaller than the sum of its proper divisors (1221378116).

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

645742524 is a wasteful number, since it uses less digits than its factorization.

645742524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 240 (or 238 counting only the distinct ones).

The product of its digits is 268800, while the sum is 39.

The square root of 645742524 is about 25411.4644206114. The cubic root of 645742524 is about 864.3436829301.

The spelling of 645742524 in words is "six hundred forty-five million, seven hundred forty-two thousand, five hundred twenty-four".