69072721 has 3 divisors (see below), whose sum is σ = 69081033. Its totient is φ = 69064410.

The previous prime is 69072713. The next prime is 69072767. The reversal of 69072721 is 12727096.

The square root of 69072721 is 8311.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 69072721 - 2³ = 69072713 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (69072791) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 4156 + ... + 12466.

It is an arithmetic number, because the mean of its divisors is an integer number (23027011).

Almost surely, 2^69072721 is an apocalyptic number.

69072721 is the 8311-st square number.

69072721 is the 4156-th centered octagonal number.

It is an amenable number.

69072721 is a deficient number, since it is larger than the sum of its proper divisors (8312).

69072721 is an frugal number, since it uses more digits than its factorization.

69072721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16622 (or 8311 counting only the distinct ones).

The product of its (nonzero) digits is 10584, while the sum is 34.

The cubic root of 69072721 is about 410.3006341549.

The spelling of 69072721 in words is "sixty-nine million, seventy-two thousand, seven hundred twenty-one".