1255719706921 has 27 divisors (see below), whose sum is σ = 1382122415791. Its totient is φ = 1140598237184.

The previous prime is 1255719706897. The next prime is 1255719706957. The reversal of 1255719706921 is 1296079175521.

The square root of 1255719706921 is 1120589.

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

It can be written as a sum of positive squares in 13 ways, for example, as 378730521 + 1255340976400 = 19461^2 + 1120420^2 .

It is not a de Polignac number, because 1255719706921 - 2¹⁷ = 1255719575849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1255719706121) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 552449241 + ... + 552451513.

Almost surely, 2^{1255719706921} is an apocalyptic number.

1255719706921 is the 1120589-th square number.

1255719706921 is the 560295-th centered octagonal number.

It is an amenable number.

1255719706921 is a deficient number, since it is larger than the sum of its proper divisors (126402708870).

1255719706921 is an frugal number, since it uses more digits than its factorization.

1255719706921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4638 (or 2319 counting only the distinct ones).

The product of its (nonzero) digits is 2381400, while the sum is 55.

The spelling of 1255719706921 in words is "one trillion, two hundred fifty-five billion, seven hundred nineteen million, seven hundred six thousand, nine hundred twenty-one".