1256436664 has 16 divisors (see below), whose sum is σ = 2692364400. Its totient is φ = 538472832.

The previous prime is 1256436641. The next prime is 1256436673. The reversal of 1256436664 is 4666346521.

It is a self number, because there is not a number n which added to its sum of digits gives 1256436664.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11218129 + ... + 11218240.

It is an arithmetic number, because the mean of its divisors is an integer number (168272775).

Almost surely, 2^1256436664 is an apocalyptic number.

1256436664 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

1256436664 is an abundant number, since it is smaller than the sum of its proper divisors (1435927736).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1256436664 is a wasteful number, since it uses less digits than its factorization.

1256436664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22436382 (or 22436378 counting only the distinct ones).

The product of its digits is 622080, while the sum is 43.

The square root of 1256436664 is about 35446.2503517650. The cubic root of 1256436664 is about 1079.0631633500.

The spelling of 1256436664 in words is "one billion, two hundred fifty-six million, four hundred thirty-six thousand, six hundred sixty-four".