21945235 has 16 divisors (see below), whose sum is σ = 28484064. Its totient is φ = 16134912.

The previous prime is 21945229. The next prime is 21945239. The reversal of 21945235 is 53254912.

It is a cyclic number.

It is not a de Polignac number, because 21945235 - 2²¹ = 19848083 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21945197 and 21945206.

It is not an unprimeable number, because it can be changed into a prime (21945239) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17799 + ... + 18991.

It is an arithmetic number, because the mean of its divisors is an integer number (1780254).

Almost surely, 2^21945235 is an apocalyptic number.

21945235 is a deficient number, since it is larger than the sum of its proper divisors (6538829).

21945235 is a wasteful number, since it uses less digits than its factorization.

21945235 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1494.

The product of its digits is 10800, while the sum is 31.

The square root of 21945235 is about 4684.5741535384. The cubic root of 21945235 is about 279.9712342898.

It can be divided in two parts, 219 and 45235, that added together give a palindrome (45454).

The spelling of 21945235 in words is "twenty-one million, nine hundred forty-five thousand, two hundred thirty-five".