100815665 has 4 divisors (see below), whose sum is σ = 120978804. Its totient is φ = 80652528.

The previous prime is 100815599. The next prime is 100815667. The reversal of 100815665 is 566518001.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 27952369 + 72863296 = 5287^2 + 8536^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-100815665 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (100815667) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10081562 + ... + 10081571.

It is an arithmetic number, because the mean of its divisors is an integer number (30244701).

Almost surely, 2^100815665 is an apocalyptic number.

It is an amenable number.

100815665 is a deficient number, since it is larger than the sum of its proper divisors (20163139).

100815665 is an equidigital number, since it uses as much as digits as its factorization.

100815665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20163138.

The product of its (nonzero) digits is 7200, while the sum is 32.

The square root of 100815665 is about 10040.7004237752. The cubic root of 100815665 is about 465.4174614636.

The spelling of 100815665 in words is "one hundred million, eight hundred fifteen thousand, six hundred sixty-five".