645522696 has 384 divisors, whose sum is σ = 2311545600. Its totient is φ = 164229120.

The previous prime is 645522677. The next prime is 645522707. The reversal of 645522696 is 696225546.

It is a happy number.

645522696 is a `hidden beast` number, since 6 + 4 + 552 + 2 + 6 + 96 = 666.

It is a super-2 number, since 2×645522696² = 833399102102216832, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 7253020 + ... + 7253108.

It is an arithmetic number, because the mean of its divisors is an integer number (6019650).

Almost surely, 2^645522696 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 645522696, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1155772800).

645522696 is an abundant number, since it is smaller than the sum of its proper divisors (1666022904).

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

645522696 is a wasteful number, since it uses less digits than its factorization.

645522696 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171 (or 155 counting only the distinct ones).

The product of its digits is 777600, while the sum is 45.

The square root of 645522696 is about 25407.1386818744. The cubic root of 645522696 is about 864.2455899073.

The spelling of 645522696 in words is "six hundred forty-five million, five hundred twenty-two thousand, six hundred ninety-six".