1263661649 has 8 divisors (see below), whose sum is σ = 1313813760. Its totient is φ = 1214096400.

The previous prime is 1263661613. The next prime is 1263661657. The reversal of 1263661649 is 9461663621.

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

It is not a de Polignac number, because 1263661649 - 2⁸ = 1263661393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1263661549) 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, 142322 + ... + 150939.

It is an arithmetic number, because the mean of its divisors is an integer number (164226720).

Almost surely, 2^1263661649 is an apocalyptic number.

It is an amenable number.

1263661649 is a deficient number, since it is larger than the sum of its proper divisors (50152111).

1263661649 is a wasteful number, since it uses less digits than its factorization.

1263661649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 293431.

The product of its digits is 279936, while the sum is 44.

The square root of 1263661649 is about 35548.0189180776. The cubic root of 1263661649 is about 1081.1275515317.

The spelling of 1263661649 in words is "one billion, two hundred sixty-three million, six hundred sixty-one thousand, six hundred forty-nine".