21117629 has 8 divisors (see below), whose sum is σ = 22781472. Its totient is φ = 19459440.

The previous prime is 21117563. The next prime is 21117631. The reversal of 21117629 is 92671112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-21117629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21117029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9542 + ... + 11544.

It is an arithmetic number, because the mean of its divisors is an integer number (2847684).

Almost surely, 2^21117629 is an apocalyptic number.

It is an amenable number.

21117629 is a deficient number, since it is larger than the sum of its proper divisors (1663843).

21117629 is a wasteful number, since it uses less digits than its factorization.

21117629 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2827.

The product of its digits is 1512, while the sum is 29.

The square root of 21117629 is about 4595.3921486637. The cubic root of 21117629 is about 276.4065849917.

The spelling of 21117629 in words is "twenty-one million, one hundred seventeen thousand, six hundred twenty-nine".