1255922721 has 9 divisors (see below), whose sum is σ = 1814264179. Its totient is φ = 837210936.

The previous prime is 1255922711. The next prime is 1255922741. The reversal of 1255922721 is 1272295521.

The square root of 1255922721 is 35439.

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

1255922721 is a `hidden beast` number, since 1 + 25 + 592 + 27 + 21 = 666.

1255922721 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., 492174225 + 763748496 = 22185^2 + 27636^2 .

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

It is a de Polignac number, because none of the positive numbers 2^k-1255922721 is a prime.

It is a super-2 number, since 2×1255922721² = 3154683762248087682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1255922711) 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, 100411 + ... + 112223.

Almost surely, 2^1255922721 is an apocalyptic number.

1255922721 is the 35439-th square number.

1255922721 is the 17720-th centered octagonal number.

It is an amenable number.

1255922721 is a deficient number, since it is larger than the sum of its proper divisors (558341458).

1255922721 is an frugal number, since it uses more digits than its factorization.

1255922721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23632 (or 11816 counting only the distinct ones).

The product of its digits is 25200, while the sum is 36.

The cubic root of 1255922721 is about 1078.9160137142.

Multiplying 1255922721 by its sum of digits (36), we get a square (45213217956 = 212634²).

The spelling of 1255922721 in words is "one billion, two hundred fifty-five million, nine hundred twenty-two thousand, seven hundred twenty-one".