29997979840638 has 32 divisors (see below), whose sum is σ = 67792044844800. Its totient is φ = 9829846500408.

The previous prime is 29997979840607. The next prime is 29997979840663. The reversal of 29997979840638 is 83604897979992.

29997979840638 is a `hidden beast` number, since 29 + 9 + 9 + 7 + 97 + 98 + 406 + 3 + 8 = 666.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4707777706 + ... + 4707784077.

It is an arithmetic number, because the mean of its divisors is an integer number (2118501401400).

Almost surely, 2^{29997979840638} is an apocalyptic number.

29997979840638 is an abundant number, since it is smaller than the sum of its proper divisors (37794065004162).

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

29997979840638 is a wasteful number, since it uses less digits than its factorization.

29997979840638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9415561853 (or 9415561847 counting only the distinct ones).

The product of its (nonzero) digits is 26665583616, while the sum is 90.

The spelling of 29997979840638 in words is "twenty-nine trillion, nine hundred ninety-seven billion, nine hundred seventy-nine million, eight hundred forty thousand, six hundred thirty-eight".