645155 has 8 divisors (see below), whose sum is σ = 884832. Its totient is φ = 442368.

The previous prime is 645149. The next prime is 645179. The reversal of 645155 is 551546.

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 645155 - 2⁶ = 645091 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 645155.

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, 9182 + ... + 9251.

It is an arithmetic number, because the mean of its divisors is an integer number (110604).

2⁶⁴⁵¹⁵⁵ is an apocalyptic number.

645155 is a deficient number, since it is larger than the sum of its proper divisors (239677).

645155 is a wasteful number, since it uses less digits than its factorization.

645155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18445.

The product of its digits is 3000, while the sum is 26.

The square root of 645155 is about 803.2154131987. The cubic root of 645155 is about 86.4081464512.

The spelling of 645155 in words is "six hundred forty-five thousand, one hundred fifty-five".