72117953 has 4 divisors (see below), whose sum is σ = 72986928. Its totient is φ = 71248980.

The previous prime is 72117943. The next prime is 72117967. The reversal of 72117953 is 35971127.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 72117953 - 2⁸ = 72117697 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (72117943) 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, 434363 + ... + 434528.

It is an arithmetic number, because the mean of its divisors is an integer number (18246732).

Almost surely, 2^72117953 is an apocalyptic number.

It is an amenable number.

72117953 is a deficient number, since it is larger than the sum of its proper divisors (868975).

72117953 is an equidigital number, since it uses as much as digits as its factorization.

72117953 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 868974.

The product of its digits is 13230, while the sum is 35.

The square root of 72117953 is about 8492.2289771296. The cubic root of 72117953 is about 416.2438185617.

The spelling of 72117953 in words is "seventy-two million, one hundred seventeen thousand, nine hundred fifty-three".