645235505 has 32 divisors (see below), whose sum is σ = 811814400. Its totient is φ = 491936512.

The previous prime is 645235501. The next prime is 645235523. The reversal of 645235505 is 505532546.

It is a cyclic number.

It is not a de Polignac number, because 645235505 - 2² = 645235501 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (645235501) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2398511 + ... + 2398779.

It is an arithmetic number, because the mean of its divisors is an integer number (25369200).

Almost surely, 2^645235505 is an apocalyptic number.

It is an amenable number.

645235505 is a deficient number, since it is larger than the sum of its proper divisors (166578895).

645235505 is a wasteful number, since it uses less digits than its factorization.

645235505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 553.

The product of its (nonzero) digits is 90000, while the sum is 35.

The square root of 645235505 is about 25401.4862754131. The cubic root of 645235505 is about 864.1174041883.

The spelling of 645235505 in words is "six hundred forty-five million, two hundred thirty-five thousand, five hundred five".