640100155 has 8 divisors (see below), whose sum is σ = 768446352. Its totient is φ = 511862688.

The previous prime is 640100141. The next prime is 640100161. The reversal of 640100155 is 551001046.

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 640100155 - 2⁹ = 640099643 is a prime.

It is a Duffinian number.

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, 13612 + ... + 38281.

It is an arithmetic number, because the mean of its divisors is an integer number (96055794).

Almost surely, 2^640100155 is an apocalyptic number.

640100155 is a deficient number, since it is larger than the sum of its proper divisors (128346197).

640100155 is a wasteful number, since it uses less digits than its factorization.

640100155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54365.

The product of its (nonzero) digits is 600, while the sum is 22.

The square root of 640100155 is about 25300.2006909036. The cubic root of 640100155 is about 861.8188272943.

The spelling of 640100155 in words is "six hundred forty million, one hundred thousand, one hundred fifty-five".