21326418 has 24 divisors (see below), whose sum is σ = 46472400. Its totient is φ = 7068024.

The previous prime is 21326413. The next prime is 21326429. The reversal of 21326418 is 81462312.

21326418 is a `hidden beast` number, since 2 + 13 + 2 + 641 + 8 = 666.

It is a super-2 number, since 2×21326418² = 909632209421448, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21326391 and 21326400.

It is not an unprimeable number, because it can be changed into a prime (21326411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 88 + ... + 6531.

It is an arithmetic number, because the mean of its divisors is an integer number (1936350).

Almost surely, 2^21326418 is an apocalyptic number.

21326418 is an abundant number, since it is smaller than the sum of its proper divisors (25145982).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21326418 is a wasteful number, since it uses less digits than its factorization.

21326418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6806 (or 6803 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The square root of 21326418 is about 4618.0534860480. The cubic root of 21326418 is about 277.3145388495.

The spelling of 21326418 in words is "twenty-one million, three hundred twenty-six thousand, four hundred eighteen".