645552198 has 12 divisors (see below), whose sum is σ = 1398696468. Its totient is φ = 215184060.

The previous prime is 645552197. The next prime is 645552211. The reversal of 645552198 is 891255546.

645552198 is a `hidden beast` number, since 6 + 4 + 5 + 552 + 1 + 98 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645552197) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 17931988 + ... + 17932023.

It is an arithmetic number, because the mean of its divisors is an integer number (116558039).

Almost surely, 2^645552198 is an apocalyptic number.

645552198 is an abundant number, since it is smaller than the sum of its proper divisors (753144270).

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

645552198 is a wasteful number, since it uses less digits than its factorization.

645552198 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35864019 (or 35864016 counting only the distinct ones).

The product of its digits is 432000, while the sum is 45.

The square root of 645552198 is about 25407.7192600989. The cubic root of 645552198 is about 864.2587557676.

It can be divided in two parts, 6455 and 52198, that added together give a triangular number (58653 = T₃₄₂).

The spelling of 645552198 in words is "six hundred forty-five million, five hundred fifty-two thousand, one hundred ninety-eight".