72506081 has 4 divisors (see below), whose sum is σ = 74274564. Its totient is φ = 70737600.

The previous prime is 72506069. The next prime is 72506087. The reversal of 72506081 is 18060527.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18060527 = 97 ⋅186191.

It can be written as a sum of positive squares in 2 ways, for example, as 1677025 + 70829056 = 1295^2 + 8416^2 .

It is a cyclic number.

It is not a de Polignac number, because 72506081 - 2¹⁰ = 72505057 is a prime.

It is a super-2 number, since 2×72506081² = 10514263563957122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72506087) 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, 884180 + ... + 884261.

It is an arithmetic number, because the mean of its divisors is an integer number (18568641).

Almost surely, 2^72506081 is an apocalyptic number.

It is an amenable number.

72506081 is a deficient number, since it is larger than the sum of its proper divisors (1768483).

72506081 is a wasteful number, since it uses less digits than its factorization.

72506081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1768482.

The product of its (nonzero) digits is 3360, while the sum is 29.

The square root of 72506081 is about 8515.0502640912. The cubic root of 72506081 is about 416.9892035612.

It can be divided in two parts, 7250 and 6081, that added together give a palindrome (13331).

The spelling of 72506081 in words is "seventy-two million, five hundred six thousand, eighty-one".