640111215 has 8 divisors (see below), whose sum is σ = 1024177968. Its totient is φ = 341392640.

The previous prime is 640111207. The next prime is 640111223. The reversal of 640111215 is 512111046.

It is an interprime number because it is at equal distance from previous prime (640111207) and next prime (640111223).

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

It is not a de Polignac number, because 640111215 - 2³ = 640111207 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 640111191 and 640111200.

It is a congruent 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, 21337026 + ... + 21337055.

It is an arithmetic number, because the mean of its divisors is an integer number (128022246).

Almost surely, 2^640111215 is an apocalyptic number.

640111215 is a deficient number, since it is larger than the sum of its proper divisors (384066753).

640111215 is a wasteful number, since it uses less digits than its factorization.

640111215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42674089.

The product of its (nonzero) digits is 240, while the sum is 21.

The square root of 640111215 is about 25300.4192653007. The cubic root of 640111215 is about 861.8237909245.

The spelling of 640111215 in words is "six hundred forty million, one hundred eleven thousand, two hundred fifteen".