21046818 has 32 divisors (see below), whose sum is σ = 45561600. Its totient is φ = 6443136.

The previous prime is 21046807. The next prime is 21046819. The reversal of 21046818 is 81864012.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21046819) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18078 + ... + 19206.

It is an arithmetic number, because the mean of its divisors is an integer number (1423800).

Almost surely, 2^21046818 is an apocalyptic number.

21046818 is an abundant number, since it is smaller than the sum of its proper divisors (24514782).

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

21046818 is a wasteful number, since it uses less digits than its factorization.

21046818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1386.

The product of its (nonzero) digits is 3072, while the sum is 30.

The square root of 21046818 is about 4587.6811135910. The cubic root of 21046818 is about 276.0972929413.

The spelling of 21046818 in words is "twenty-one million, forty-six thousand, eight hundred eighteen".