21913235 has 4 divisors (see below), whose sum is σ = 26295888. Its totient is φ = 17530584.

The previous prime is 21913201. The next prime is 21913237. The reversal of 21913235 is 53231912.

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 21913235 - 2¹⁰ = 21912211 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21913237) 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, 2191319 + ... + 2191328.

It is an arithmetic number, because the mean of its divisors is an integer number (6573972).

Almost surely, 2^21913235 is an apocalyptic number.

21913235 is a deficient number, since it is larger than the sum of its proper divisors (4382653).

21913235 is an equidigital number, since it uses as much as digits as its factorization.

21913235 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4382652.

The product of its digits is 1620, while the sum is 26.

The square root of 21913235 is about 4681.1574423427. The cubic root of 21913235 is about 279.8350857110.

The spelling of 21913235 in words is "twenty-one million, nine hundred thirteen thousand, two hundred thirty-five".