21365029 has 12 divisors (see below), whose sum is σ = 24928608. Its totient is φ = 18257400.

The previous prime is 21365017. The next prime is 21365033. The reversal of 21365029 is 92056312.

It is not a de Polignac number, because 21365029 - 2⁹ = 21364517 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21364988 and 21365006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21365009) 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, 30574 + ... + 31264.

It is an arithmetic number, because the mean of its divisors is an integer number (2077384).

Almost surely, 2^21365029 is an apocalyptic number.

It is an amenable number.

21365029 is a deficient number, since it is larger than the sum of its proper divisors (3563579).

21365029 is an equidigital number, since it uses as much as digits as its factorization.

21365029 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1336 (or 1329 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 21365029 is about 4622.2320365815. The cubic root of 21365029 is about 277.4817951967.

The spelling of 21365029 in words is "twenty-one million, three hundred sixty-five thousand, twenty-nine".