21480018 has 32 divisors (see below), whose sum is σ = 49496064. Its totient is φ = 6087312.

The previous prime is 21480007. The next prime is 21480049. The reversal of 21480018 is 81008412.

It is a super-2 number, since 2×21480018² = 922782346560648, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21480018.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 3321 + ... + 7347.

It is an arithmetic number, because the mean of its divisors is an integer number (1546752).

Almost surely, 2^21480018 is an apocalyptic number.

21480018 is an abundant number, since it is smaller than the sum of its proper divisors (28016046).

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

21480018 is a wasteful number, since it uses less digits than its factorization.

21480018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4166.

The product of its (nonzero) digits is 512, while the sum is 24.

The square root of 21480018 is about 4634.6540323955. The cubic root of 21480018 is about 277.9787175537.

The spelling of 21480018 in words is "twenty-one million, four hundred eighty thousand, eighteen".