21910433 has 4 divisors (see below), whose sum is σ = 23199300. Its totient is φ = 20621568.

The previous prime is 21910409. The next prime is 21910453. The reversal of 21910433 is 33401912.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15108769 + 6801664 = 3887^2 + 2608^2 .

It is a cyclic number.

It is not a de Polignac number, because 21910433 - 2¹² = 21906337 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21910399 and 21910408.

It is not an unprimeable number, because it can be changed into a prime (21910453) 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, 644408 + ... + 644441.

It is an arithmetic number, because the mean of its divisors is an integer number (5799825).

Almost surely, 2^21910433 is an apocalyptic number.

It is an amenable number.

21910433 is a deficient number, since it is larger than the sum of its proper divisors (1288867).

21910433 is a wasteful number, since it uses less digits than its factorization.

21910433 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1288866.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 21910433 is about 4680.8581478186. The cubic root of 21910433 is about 279.8231578916.

The spelling of 21910433 in words is "twenty-one million, nine hundred ten thousand, four hundred thirty-three".