645122550 has 48 divisors (see below), whose sum is σ = 1637127360. Its totient is φ = 168030240.

The previous prime is 645122531. The next prime is 645122557. The reversal of 645122550 is 55221546.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645122557) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 43560 + ... + 56459.

It is an arithmetic number, because the mean of its divisors is an integer number (34106820).

Almost surely, 2^645122550 is an apocalyptic number.

645122550 is an abundant number, since it is smaller than the sum of its proper divisors (992004810).

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

645122550 is a wasteful number, since it uses less digits than its factorization.

645122550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100077 (or 100072 counting only the distinct ones).

The product of its (nonzero) digits is 12000, while the sum is 30.

The square root of 645122550 is about 25399.2627845770. The cubic root of 645122550 is about 864.0669770823.

The spelling of 645122550 in words is "six hundred forty-five million, one hundred twenty-two thousand, five hundred fifty".