21364039 has 4 divisors (see below), whose sum is σ = 22100760. Its totient is φ = 20627320.

The previous prime is 21364009. The next prime is 21364061. The reversal of 21364039 is 93046312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21364039 - 2²¹ = 19266887 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21363998 and 21364016.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21364009) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 368317 + ... + 368374.

It is an arithmetic number, because the mean of its divisors is an integer number (5525190).

Almost surely, 2^21364039 is an apocalyptic number.

21364039 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

21364039 is a deficient number, since it is larger than the sum of its proper divisors (736721).

21364039 is an equidigital number, since it uses as much as digits as its factorization.

21364039 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 736720.

The product of its (nonzero) digits is 3888, while the sum is 28.

The square root of 21364039 is about 4622.1249442221. The cubic root of 21364039 is about 277.4775092018.

The spelling of 21364039 in words is "twenty-one million, three hundred sixty-four thousand, thirty-nine".