1263642728 has 32 divisors (see below), whose sum is σ = 2518276800. Its totient is φ = 592748928.

The previous prime is 1263642697. The next prime is 1263642791. The reversal of 1263642728 is 8272463621.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24701 + ... + 56012.

It is an arithmetic number, because the mean of its divisors is an integer number (78696150).

Almost surely, 2^1263642728 is an apocalyptic number.

It is an amenable number.

1263642728 is a deficient number, since it is larger than the sum of its proper divisors (1254634072).

1263642728 is a wasteful number, since it uses less digits than its factorization.

1263642728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80841 (or 80837 counting only the distinct ones).

The product of its digits is 193536, while the sum is 41.

The square root of 1263642728 is about 35547.7527841072. The cubic root of 1263642728 is about 1081.1221555418.

The spelling of 1263642728 in words is "one billion, two hundred sixty-three million, six hundred forty-two thousand, seven hundred twenty-eight".