21084692220 has 72 divisors (see below), whose sum is σ = 64349362896. Its totient is φ = 5588082432.

The previous prime is 21084692207. The next prime is 21084692263. The reversal of 21084692220 is 2229648012.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 329977 + ... + 388656.

Almost surely, 2^21084692220 is an apocalyptic number.

21084692220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21084692220 is an abundant number, since it is smaller than the sum of its proper divisors (43264670676).

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

21084692220 is a wasteful number, since it uses less digits than its factorization.

21084692220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 718811 (or 718806 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The spelling of 21084692220 in words is "twenty-one billion, eighty-four million, six hundred ninety-two thousand, two hundred twenty".