21792385 has 32 divisors (see below), whose sum is σ = 29486592. Its totient is φ = 15375360.

The previous prime is 21792383. The next prime is 21792391. The reversal of 21792385 is 58329712.

It is not a de Polignac number, because 21792385 - 2¹ = 21792383 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21792383) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 138727 + ... + 138883.

It is an arithmetic number, because the mean of its divisors is an integer number (921456).

Almost surely, 2^21792385 is an apocalyptic number.

It is an amenable number.

21792385 is a deficient number, since it is larger than the sum of its proper divisors (7694207).

21792385 is a wasteful number, since it uses less digits than its factorization.

21792385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 273.

The product of its digits is 30240, while the sum is 37.

The square root of 21792385 is about 4668.2314638415. The cubic root of 21792385 is about 279.3197133131.

It can be divided in two parts, 2179 and 2385, that multiplied together give a palindrome (5196915).

The spelling of 21792385 in words is "twenty-one million, seven hundred ninety-two thousand, three hundred eighty-five".