72342521 has 4 divisors (see below), whose sum is σ = 75487872. Its totient is φ = 69197172.

The previous prime is 72342451. The next prime is 72342553. The reversal of 72342521 is 12524327.

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: 12524327 = 211 ⋅59357.

It is a cyclic number.

It is not a de Polignac number, because 72342521 - 2¹⁰ = 72341497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72342581) 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, 1572641 + ... + 1572686.

It is an arithmetic number, because the mean of its divisors is an integer number (18871968).

Almost surely, 2^72342521 is an apocalyptic number.

It is an amenable number.

72342521 is a deficient number, since it is larger than the sum of its proper divisors (3145351).

72342521 is a wasteful number, since it uses less digits than its factorization.

72342521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3145350.

The product of its digits is 3360, while the sum is 26.

The square root of 72342521 is about 8505.4406705355. The cubic root of 72342521 is about 416.6754179140.

Adding to 72342521 its reverse (12524327), we get a palindrome (84866848).

The spelling of 72342521 in words is "seventy-two million, three hundred forty-two thousand, five hundred twenty-one".