1263902649 has 4 divisors (see below), whose sum is σ = 1685203536. Its totient is φ = 842601764.

The previous prime is 1263902641. The next prime is 1263902659. The reversal of 1263902649 is 9462093621.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 9462093621 = 3 ⋅3154031207.

It is a cyclic number.

It is not a de Polignac number, because 1263902649 - 2³ = 1263902641 is a prime.

It is a super-2 number, since 2×1263902649² = 3194899812298434402, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1263902649.

It is not an unprimeable number, because it can be changed into a prime (1263902641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 210650439 + ... + 210650444.

It is an arithmetic number, because the mean of its divisors is an integer number (421300884).

Almost surely, 2^1263902649 is an apocalyptic number.

It is an amenable number.

1263902649 is a deficient number, since it is larger than the sum of its proper divisors (421300887).

1263902649 is an equidigital number, since it uses as much as digits as its factorization.

1263902649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 421300886.

The product of its (nonzero) digits is 139968, while the sum is 42.

The square root of 1263902649 is about 35551.4085374968. The cubic root of 1263902649 is about 1081.1962764624.

The spelling of 1263902649 in words is "one billion, two hundred sixty-three million, nine hundred two thousand, six hundred forty-nine".