1278458631 has 12 divisors (see below), whose sum is σ = 1906232640. Its totient is φ = 824811840.

The previous prime is 1278458627. The next prime is 1278458639. The reversal of 1278458631 is 1368548721.

1278458631 is a `hidden beast` number, since 1 + 2 + 7 + 8 + 4 + 5 + 8 + 631 = 666.

It is not a de Polignac number, because 1278458631 - 2² = 1278458627 is a prime.

It is a super-2 number, since 2×1278458631² = 3268912942356788322, which contains 22 as substring.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1278458639) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2290866 + ... + 2291423.

It is an arithmetic number, because the mean of its divisors is an integer number (158852720).

Almost surely, 2^1278458631 is an apocalyptic number.

1278458631 is a deficient number, since it is larger than the sum of its proper divisors (627774009).

1278458631 is a wasteful number, since it uses less digits than its factorization.

1278458631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4582326 (or 4582323 counting only the distinct ones).

The product of its digits is 322560, while the sum is 45.

The square root of 1278458631 is about 35755.5398644741. The cubic root of 1278458631 is about 1085.3310466683.

The spelling of 1278458631 in words is "one billion, two hundred seventy-eight million, four hundred fifty-eight thousand, six hundred thirty-one".