21455426 has 12 divisors (see below), whose sum is σ = 32521398. Its totient is φ = 10616112.

The previous prime is 21455393. The next prime is 21455429. The reversal of 21455426 is 62455412.

It can be written as a sum of positive squares in only one way, i.e., 21169201 + 286225 = 4601^2 + 535^2 .

It is a hoax number, since the sum of its digits (29) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21455429) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 22430 + ... + 23366.

Almost surely, 2^21455426 is an apocalyptic number.

21455426 is a deficient number, since it is larger than the sum of its proper divisors (11065972).

21455426 is an equidigital number, since it uses as much as digits as its factorization.

21455426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1153 (or 1046 counting only the distinct ones).

The product of its digits is 9600, while the sum is 29.

The square root of 21455426 is about 4632.0002158895. Note that the first 3 decimals coincide. The cubic root of 21455426 is about 277.8725931377.

The spelling of 21455426 in words is "twenty-one million, four hundred fifty-five thousand, four hundred twenty-six".