645198522 has 8 divisors (see below), whose sum is σ = 1290397056. Its totient is φ = 215066172.

The previous prime is 645198503. The next prime is 645198529. The reversal of 645198522 is 225891546.

It is a sphenic number, since it is the product of 3 distinct primes.

645198522 is an admirable number.

It is a super-2 number, since 2×645198522² = 832562265581968968, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (645198529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53766538 + ... + 53766549.

It is an arithmetic number, because the mean of its divisors is an integer number (161299632).

Almost surely, 2^645198522 is an apocalyptic number.

645198522 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

645198522 is a wasteful number, since it uses less digits than its factorization.

645198522 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107533092.

The product of its digits is 172800, while the sum is 42.

The square root of 645198522 is about 25400.7582957675. The cubic root of 645198522 is about 864.1008943175.

The spelling of 645198522 in words is "six hundred forty-five million, one hundred ninety-eight thousand, five hundred twenty-two".