1392110721 has 9 divisors (see below), whose sum is σ = 2010988291. Its totient is φ = 927999192.

The previous prime is 1392110711. The next prime is 1392110747. The reversal of 1392110721 is 1270112931.

The square root of 1392110721 is 37311.

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

1392110721 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 49914225 + 1342196496 = 7065^2 + 36636^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 1392110721 - 2⁵ = 1392110689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1392110701) 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, 105715 + ... + 118151.

Almost surely, 2^1392110721 is an apocalyptic number.

1392110721 is the 37311-st square number.

1392110721 is the 18656-th centered octagonal number.

It is an amenable number.

1392110721 is a deficient number, since it is larger than the sum of its proper divisors (618877570).

1392110721 is an frugal number, since it uses more digits than its factorization.

1392110721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24880 (or 12440 counting only the distinct ones).

The product of its (nonzero) digits is 756, while the sum is 27.

The cubic root of 1392110721 is about 1116.5836374690.

It can be divided in two parts, 13921 and 10721, that added together give a palindrome (24642).

The spelling of 1392110721 in words is "one billion, three hundred ninety-two million, one hundred ten thousand, seven hundred twenty-one".