1297639404 has 18 divisors (see below), whose sum is σ = 3280144140. Its totient is φ = 432546456.

The previous prime is 1297639379. The next prime is 1297639417. The reversal of 1297639404 is 4049367921.

It is a happy number.

1297639404 is a `hidden beast` number, since 1 + 2 + 9 + 7 + 639 + 4 + 0 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

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

It is a self number, because there is not a number n which added to its sum of digits gives 1297639404.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 18022734 + ... + 18022805.

It is an arithmetic number, because the mean of its divisors is an integer number (182230230).

Almost surely, 2^1297639404 is an apocalyptic number.

It is an amenable number.

1297639404 is an abundant number, since it is smaller than the sum of its proper divisors (1982504736).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1297639404 is a wasteful number, since it uses less digits than its factorization.

1297639404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36045549 (or 36045544 counting only the distinct ones).

The product of its (nonzero) digits is 326592, while the sum is 45.

The square root of 1297639404 is about 36022.7623038545. The cubic root of 1297639404 is about 1090.7318834053.

The spelling of 1297639404 in words is "one billion, two hundred ninety-seven million, six hundred thirty-nine thousand, four hundred four".