645022155 has 8 divisors (see below), whose sum is σ = 1032035472. Its totient is φ = 344011808.

The previous prime is 645022117. The next prime is 645022171. The reversal of 645022155 is 551220546.

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

It is a cyclic number.

It is not a de Polignac number, because 645022155 - 2¹⁴ = 645005771 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21500724 + ... + 21500753.

It is an arithmetic number, because the mean of its divisors is an integer number (129004434).

Almost surely, 2^645022155 is an apocalyptic number.

645022155 is a deficient number, since it is larger than the sum of its proper divisors (387013317).

645022155 is a wasteful number, since it uses less digits than its factorization.

645022155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43001485.

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

The square root of 645022155 is about 25397.2863707917. The cubic root of 645022155 is about 864.0221522634.

The spelling of 645022155 in words is "six hundred forty-five million, twenty-two thousand, one hundred fifty-five".