21455356 has 12 divisors (see below), whose sum is σ = 40435192. Its totient is φ = 9902448.

The previous prime is 21455353. The next prime is 21455363. The reversal of 21455356 is 65355412.

It is a plaindrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21455353) 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, 206250 + ... + 206353.

Almost surely, 2^21455356 is an apocalyptic number.

21455356 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21455356 is a deficient number, since it is larger than the sum of its proper divisors (18979836).

21455356 is a wasteful number, since it uses less digits than its factorization.

21455356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 412620 (or 412618 counting only the distinct ones).

The product of its digits is 18000, while the sum is 31.

The square root of 21455356 is about 4631.9926597524. The cubic root of 21455356 is about 277.8722909437.

The spelling of 21455356 in words is "twenty-one million, four hundred fifty-five thousand, three hundred fifty-six".