72170805 has 16 divisors (see below), whose sum is σ = 131969664. Its totient is φ = 32992320.

The previous prime is 72170801. The next prime is 72170807. The reversal of 72170805 is 50807127.

It is a happy number.

It is not a de Polignac number, because 72170805 - 2² = 72170801 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72170801) 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, 343566 + ... + 343775.

It is an arithmetic number, because the mean of its divisors is an integer number (8248104).

Almost surely, 2^72170805 is an apocalyptic number.

It is an amenable number.

72170805 is a deficient number, since it is larger than the sum of its proper divisors (59798859).

72170805 is a wasteful number, since it uses less digits than its factorization.

72170805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 687356.

The product of its (nonzero) digits is 3920, while the sum is 30.

The square root of 72170805 is about 8495.3401933060. The cubic root of 72170805 is about 416.3454758489.

The spelling of 72170805 in words is "seventy-two million, one hundred seventy thousand, eight hundred five".