72617509 has 4 divisors (see below), whose sum is σ = 75774816. Its totient is φ = 69460204.

The previous prime is 72617483. The next prime is 72617513. The reversal of 72617509 is 90571627.

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: 90571627 = 191 ⋅474197.

It is a cyclic number.

It is not a de Polignac number, because 72617509 - 2¹⁵ = 72584741 is a prime.

It is a super-2 number, since 2×72617509² = 10546605226730162, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72617539) 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, 1578619 + ... + 1578664.

It is an arithmetic number, because the mean of its divisors is an integer number (18943704).

Almost surely, 2^72617509 is an apocalyptic number.

It is an amenable number.

72617509 is a deficient number, since it is larger than the sum of its proper divisors (3157307).

72617509 is a wasteful number, since it uses less digits than its factorization.

72617509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3157306.

The product of its (nonzero) digits is 26460, while the sum is 37.

The square root of 72617509 is about 8521.5907552522. The cubic root of 72617509 is about 417.2027051526.

The spelling of 72617509 in words is "seventy-two million, six hundred seventeen thousand, five hundred nine".