72174521 has 4 divisors (see below), whose sum is σ = 75973200. Its totient is φ = 68375844.

The previous prime is 72174517. The next prime is 72174547. The reversal of 72174521 is 12547127.

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: 12547127 = 197 ⋅63691.

It is a cyclic number.

It is not a de Polignac number, because 72174521 - 2² = 72174517 is a prime.

It is a super-2 number, since 2×72174521² = 10418322963158882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72174551) 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, 1899311 + ... + 1899348.

It is an arithmetic number, because the mean of its divisors is an integer number (18993300).

Almost surely, 2^72174521 is an apocalyptic number.

It is an amenable number.

72174521 is a deficient number, since it is larger than the sum of its proper divisors (3798679).

72174521 is a wasteful number, since it uses less digits than its factorization.

72174521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3798678.

The product of its digits is 3920, while the sum is 29.

The square root of 72174521 is about 8495.5588986246. The cubic root of 72174521 is about 416.3526214587.

The spelling of 72174521 in words is "seventy-two million, one hundred seventy-four thousand, five hundred twenty-one".