21669700 has 72 divisors (see below), whose sum is σ = 51524480. Its totient is φ = 7862400.

The previous prime is 21669691. The next prime is 21669719. The reversal of 21669700 is 796612.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

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 23 ways as a sum of consecutive naturals, for example, 102595 + ... + 102805.

Almost surely, 2^21669700 is an apocalyptic number.

21669700 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 21669700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25762240).

21669700 is an abundant number, since it is smaller than the sum of its proper divisors (29854780).

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

21669700 is a wasteful number, since it uses less digits than its factorization.

21669700 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 317 (or 310 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 31.

The square root of 21669700 is about 4655.0725021207. The cubic root of 21669700 is about 278.7945627777.

The spelling of 21669700 in words is "twenty-one million, six hundred sixty-nine thousand, seven hundred".