1263799156 has 6 divisors (see below), whose sum is σ = 2211648530. Its totient is φ = 631899576.

The previous prime is 1263799153. The next prime is 1263799169. The reversal of 1263799156 is 6519973621.

It can be written as a sum of positive squares in only one way, i.e., 674960400 + 588838756 = 25980^2 + 24266^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1263799153) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 157974891 + ... + 157974898.

Almost surely, 2^1263799156 is an apocalyptic number.

It is an amenable number.

1263799156 is a deficient number, since it is larger than the sum of its proper divisors (947849374).

1263799156 is a wasteful number, since it uses less digits than its factorization.

1263799156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 315949793 (or 315949791 counting only the distinct ones).

The product of its digits is 612360, while the sum is 49.

The square root of 1263799156 is about 35549.9529676201. The cubic root of 1263799156 is about 1081.1667648803.

The spelling of 1263799156 in words is "one billion, two hundred sixty-three million, seven hundred ninety-nine thousand, one hundred fifty-six".