1263728960649 has 9 divisors (see below), whose sum is σ = 1825391147853. Its totient is φ = 842483725452.

The previous prime is 1263728960581. The next prime is 1263728960651. The reversal of 1263728960649 is 9460698273621.

The square root of 1263728960649 is 1124157.

It is a perfect power (a square), and thus also a powerful number.

1263728960649 is a `hidden beast` number, since 12 + 6 + 3 + 7 + 2 + 8 + 9 + 606 + 4 + 9 = 666.

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 1263728960649 - 2⁷ = 1263728960521 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1263728960699) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3185112 + ... + 3559830.

Almost surely, 2^{1263728960649} is an apocalyptic number.

1263728960649 is the 1124157-th square number.

1263728960649 is the 562079-th centered octagonal number.

It is an amenable number.

1263728960649 is a deficient number, since it is larger than the sum of its proper divisors (561662187204).

1263728960649 is an frugal number, since it uses more digits than its factorization.

1263728960649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 749444 (or 374722 counting only the distinct ones).

The product of its (nonzero) digits is 47029248, while the sum is 63.

The spelling of 1263728960649 in words is "one trillion, two hundred sixty-three billion, seven hundred twenty-eight million, nine hundred sixty thousand, six hundred forty-nine".