21469820 has 12 divisors (see below), whose sum is σ = 45086664. Its totient is φ = 8587920.

The previous prime is 21469807. The next prime is 21469843. The reversal of 21469820 is 2896412.

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 536726 + ... + 536765.

It is an arithmetic number, because the mean of its divisors is an integer number (3757222).

Almost surely, 2^21469820 is an apocalyptic number.

21469820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21469820 is an abundant number, since it is smaller than the sum of its proper divisors (23616844).

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

21469820 is a wasteful number, since it uses less digits than its factorization.

21469820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1073500 (or 1073498 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 21469820 is about 4633.5537117854. The cubic root of 21469820 is about 277.9347188986.

The spelling of 21469820 in words is "twenty-one million, four hundred sixty-nine thousand, eight hundred twenty".