640066115 has 16 divisors (see below), whose sum is σ = 827714496. Its totient is φ = 472348800.

The previous prime is 640066111. The next prime is 640066121. The reversal of 640066115 is 511660046.

It is not a de Polignac number, because 640066115 - 2² = 640066111 is a prime.

It is a Smith number, since the sum of its digits (29) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640066111) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 148085 + ... + 152345.

It is an arithmetic number, because the mean of its divisors is an integer number (51732156).

Almost surely, 2^640066115 is an apocalyptic number.

640066115 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

640066115 is a deficient number, since it is larger than the sum of its proper divisors (187648381).

640066115 is a wasteful number, since it uses less digits than its factorization.

640066115 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6590.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 640066115 is about 25299.5279600233. The cubic root of 640066115 is about 861.8035500846.

The spelling of 640066115 in words is "six hundred forty million, sixty-six thousand, one hundred fifteen".