21129737634 has 24 divisors (see below), whose sum is σ = 45796633740. Its totient is φ = 7040855808.

The previous prime is 21129737627. The next prime is 21129737663. The reversal of 21129737634 is 43673792112.

21129737634 is a `hidden beast` number, since 2 + 1 + 1 + 2 + 9 + 7 + 3 + 7 + 634 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 17462829609 + 3666908025 = 132147^2 + 60555^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21129737634.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 144247 + ... + 251130.

Almost surely, 2^21129737634 is an apocalyptic number.

21129737634 is an abundant number, since it is smaller than the sum of its proper divisors (24666896106).

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

21129737634 is a wasteful number, since it uses less digits than its factorization.

21129737634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 398354 (or 398351 counting only the distinct ones).

The product of its digits is 381024, while the sum is 45.

The spelling of 21129737634 in words is "twenty-one billion, one hundred twenty-nine million, seven hundred thirty-seven thousand, six hundred thirty-four".