1256773401 has 63 divisors (see below), whose sum is σ = 2060795757. Its totient is φ = 765741600.

The previous prime is 1256773391. The next prime is 1256773409. The reversal of 1256773401 is 1043776521.

It is a happy number.

The square root of 1256773401 is 35451.

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

1256773401 is a `hidden beast` number, since 125 + 67 + 73 + 401 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 47403225 + 1209370176 = 6885^2 + 34776^2 .

It is not a de Polignac number, because 1256773401 - 2²¹ = 1254676249 is a prime.

It is a super-2 number, since 2×1256773401² = 3158958762922213602, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1256773409) by changing a digit.

It is a polite number, since it can be written in 62 ways as a sum of consecutive naturals, for example, 12443251 + ... + 12443351.

Almost surely, 2^1256773401 is an apocalyptic number.

1256773401 is the 35451-st square number.

1256773401 is the 17726-th centered octagonal number.

It is an amenable number.

1256773401 is a deficient number, since it is larger than the sum of its proper divisors (804022356).

1256773401 is an frugal number, since it uses more digits than its factorization.

1256773401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246 (or 117 counting only the distinct ones).

The product of its (nonzero) digits is 35280, while the sum is 36.

The cubic root of 1256773401 is about 1079.1595544764.

Multiplying 1256773401 by its sum of digits (36), we get a square (45243842436 = 212706²).

The spelling of 1256773401 in words is "one billion, two hundred fifty-six million, seven hundred seventy-three thousand, four hundred one".