1256990399 has 8 divisors (see below), whose sum is σ = 1436889120. Its totient is φ = 1077173856.

The previous prime is 1256990377. The next prime is 1256990407. The reversal of 1256990399 is 9930996521.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1256990399 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1256990399.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1256990309) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16757 + ... + 52865.

It is an arithmetic number, because the mean of its divisors is an integer number (179611140).

Almost surely, 2^1256990399 is an apocalyptic number.

1256990399 is a deficient number, since it is larger than the sum of its proper divisors (179898721).

1256990399 is an equidigital number, since it uses as much as digits as its factorization.

1256990399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41089.

The product of its (nonzero) digits is 1180980, while the sum is 53.

The square root of 1256990399 is about 35454.0604021599. The cubic root of 1256990399 is about 1079.2216611347.

The spelling of 1256990399 in words is "one billion, two hundred fifty-six million, nine hundred ninety thousand, three hundred ninety-nine".