21829761 has 12 divisors (see below), whose sum is σ = 32203392. Its totient is φ = 14243256.

The previous prime is 21829729. The next prime is 21829763. The reversal of 21829761 is 16792812.

It is not a de Polignac number, because 21829761 - 2⁵ = 21829729 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (21829763) 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, 25381 + ... + 26226.

It is an arithmetic number, because the mean of its divisors is an integer number (2683616).

Almost surely, 2^21829761 is an apocalyptic number.

It is an amenable number.

21829761 is a deficient number, since it is larger than the sum of its proper divisors (10373631).

21829761 is a wasteful number, since it uses less digits than its factorization.

21829761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51660 (or 51657 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 21829761 is about 4672.2329779239. The cubic root of 21829761 is about 279.4793086770.

The spelling of 21829761 in words is "twenty-one million, eight hundred twenty-nine thousand, seven hundred sixty-one".