73290721 has 9 divisors (see below), whose sum is σ = 85326321. Its totient is φ = 62769252.

The previous prime is 73290713. The next prime is 73290731. The reversal of 73290721 is 12709237.

The square root of 73290721 is 8561.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 73290721 - 2³ = 73290713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (73290731) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 59316 + ... + 60538.

Almost surely, 2^73290721 is an apocalyptic number.

73290721 is the 8561-st square number.

73290721 is the 4281-st centered octagonal number.

It is an amenable number.

73290721 is a deficient number, since it is larger than the sum of its proper divisors (12035600).

73290721 is an frugal number, since it uses more digits than its factorization.

73290721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2460 (or 1230 counting only the distinct ones).

The product of its (nonzero) digits is 5292, while the sum is 31.

The cubic root of 73290721 is about 418.4879891800.

Adding to 73290721 its reverse (12709237), we get a palindrome (85999958).

The spelling of 73290721 in words is "seventy-three million, two hundred ninety thousand, seven hundred twenty-one".