21326718 has 16 divisors (see below), whose sum is σ = 48746880. Its totient is φ = 6093336.

The previous prime is 21326713. The next prime is 21326743. The reversal of 21326718 is 81762312.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21326713) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 253848 + ... + 253931.

It is an arithmetic number, because the mean of its divisors is an integer number (3046680).

Almost surely, 2^21326718 is an apocalyptic number.

21326718 is an abundant number, since it is smaller than the sum of its proper divisors (27420162).

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

21326718 is a wasteful number, since it uses less digits than its factorization.

21326718 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 507791.

The product of its digits is 4032, while the sum is 30.

The square root of 21326718 is about 4618.0859671513. The cubic root of 21326718 is about 277.3158391768.

The spelling of 21326718 in words is "twenty-one million, three hundred twenty-six thousand, seven hundred eighteen".