21469980 has 192 divisors, whose sum is σ = 75866112. Its totient is φ = 4423680.

The previous prime is 21469969. The next prime is 21469999. The reversal of 21469980 is 8996412.

It is a Saint-Exupery number, since it is equal to the product of the sides of a Pythagorean triangle: 485 × 93 × 476.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 221292 + ... + 221388.

It is an arithmetic number, because the mean of its divisors is an integer number (395136).

Almost surely, 2^21469980 is an apocalyptic number.

21469980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21469980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37933056).

21469980 is an abundant number, since it is smaller than the sum of its proper divisors (54396132).

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

21469980 is a wasteful number, since it uses less digits than its factorization.

21469980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164 (or 162 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 39.

The square root of 21469980 is about 4633.5709771191. The cubic root of 21469980 is about 277.9354093165.

The spelling of 21469980 in words is "twenty-one million, four hundred sixty-nine thousand, nine hundred eighty".