72164081 has 4 divisors (see below), whose sum is σ = 78724464. Its totient is φ = 65603700.

The previous prime is 72164047. The next prime is 72164107. The reversal of 72164081 is 18046127.

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, and also an emirpimes, since its reverse is a distinct semiprime: 18046127 = 11 ⋅1640557.

It is a cyclic number.

It is not a de Polignac number, because 72164081 - 2⁶ = 72164017 is a prime.

It is a super-2 number, since 2×72164081² = 10415309173149122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72164011) 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, 3280175 + ... + 3280196.

It is an arithmetic number, because the mean of its divisors is an integer number (19681116).

Almost surely, 2^72164081 is an apocalyptic number.

It is an amenable number.

72164081 is a deficient number, since it is larger than the sum of its proper divisors (6560383).

72164081 is a wasteful number, since it uses less digits than its factorization.

72164081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6560382.

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 72164081 is about 8494.9444377229. The cubic root of 72164081 is about 416.3325454406.

The spelling of 72164081 in words is "seventy-two million, one hundred sixty-four thousand, eighty-one".