1261262399 has 2 divisors, whose sum is σ = 1261262400. Its totient is φ = 1261262398.

The previous prime is 1261262371. The next prime is 1261262449. The reversal of 1261262399 is 9932621621.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1261262399 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1261262309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630631199 + 630631200.

It is an arithmetic number, because the mean of its divisors is an integer number (630631200).

Almost surely, 2^1261262399 is an apocalyptic number.

1261262399 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261262399 is an equidigital number, since it uses as much as digits as its factorization.

1261262399 is an evil number, because the sum of its binary digits is even.

The product of its digits is 69984, while the sum is 41.

The square root of 1261262399 is about 35514.2562782891. The cubic root of 1261262399 is about 1080.4428907693.

The spelling of 1261262399 in words is "one billion, two hundred sixty-one million, two hundred sixty-two thousand, three hundred ninety-nine".