21896243 has 4 divisors (see below), whose sum is σ = 21914520. Its totient is φ = 21877968.

The previous prime is 21896239. The next prime is 21896249. The reversal of 21896243 is 34269812.

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 21896243 - 2² = 21896239 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21896249) 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, 7205 + ... + 9782.

It is an arithmetic number, because the mean of its divisors is an integer number (5478630).

Almost surely, 2^21896243 is an apocalyptic number.

21896243 is a deficient number, since it is larger than the sum of its proper divisors (18277).

21896243 is a wasteful number, since it uses less digits than its factorization.

21896243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18276.

The product of its digits is 20736, while the sum is 35.

The square root of 21896243 is about 4679.3421546196. The cubic root of 21896243 is about 279.7627369328.

The spelling of 21896243 in words is "twenty-one million, eight hundred ninety-six thousand, two hundred forty-three".