1256761465 has 16 divisors (see below), whose sum is σ = 1602621072. Its totient is φ = 942833664.

The previous prime is 1256761447. The next prime is 1256761501. The reversal of 1256761465 is 5641676521.

It can be written as a sum of positive squares in 8 ways, for example, as 91699776 + 1165061689 = 9576^2 + 34133^2 .

It is a cyclic number.

It is not a de Polignac number, because 1256761465 - 2⁵ = 1256761433 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3144 + ... + 50233.

It is an arithmetic number, because the mean of its divisors is an integer number (100163817).

Almost surely, 2^1256761465 is an apocalyptic number.

It is an amenable number.

1256761465 is a deficient number, since it is larger than the sum of its proper divisors (345859607).

1256761465 is a wasteful number, since it uses less digits than its factorization.

1256761465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53676.

The product of its digits is 302400, while the sum is 43.

The square root of 1256761465 is about 35450.8316545607. The cubic root of 1256761465 is about 1079.1561380851.

The spelling of 1256761465 in words is "one billion, two hundred fifty-six million, seven hundred sixty-one thousand, four hundred sixty-five".