21396575 has 6 divisors (see below), whose sum is σ = 26531784. Its totient is φ = 17117240.

The previous prime is 21396569. The next prime is 21396587. The reversal of 21396575 is 57569312.

It is a happy number.

It is not a de Polignac number, because 21396575 - 2⁶ = 21396511 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 427907 + ... + 427956.

It is an arithmetic number, because the mean of its divisors is an integer number (4421964).

Almost surely, 2^21396575 is an apocalyptic number.

21396575 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21396575 is a deficient number, since it is larger than the sum of its proper divisors (5135209).

21396575 is an equidigital number, since it uses as much as digits as its factorization.

21396575 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 855873 (or 855868 counting only the distinct ones).

The product of its digits is 56700, while the sum is 38.

The square root of 21396575 is about 4625.6431985185. The cubic root of 21396575 is about 277.6182976406.

The spelling of 21396575 in words is "twenty-one million, three hundred ninety-six thousand, five hundred seventy-five".