1278632901 has 24 divisors (see below), whose sum is σ = 2135741664. Its totient is φ = 674442720.

The previous prime is 1278632879. The next prime is 1278632903. The reversal of 1278632901 is 1092368721.

It is not a de Polignac number, because 1278632901 - 2⁵ = 1278632869 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 1278632901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1278632903) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 332635 + ... + 336456.

It is an arithmetic number, because the mean of its divisors is an integer number (88989236).

Almost surely, 2^1278632901 is an apocalyptic number.

It is an amenable number.

1278632901 is a deficient number, since it is larger than the sum of its proper divisors (857108763).

1278632901 is a wasteful number, since it uses less digits than its factorization.

1278632901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 669121 (or 669114 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 39.

The square root of 1278632901 is about 35757.9767464548. The cubic root of 1278632901 is about 1085.3803591876.

The spelling of 1278632901 in words is "one billion, two hundred seventy-eight million, six hundred thirty-two thousand, nine hundred one".