21698700 has 72 divisors (see below), whose sum is σ = 63329280. Its totient is φ = 5736000.

The previous prime is 21698689. The next prime is 21698707. The reversal of 21698700 is 789612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21698707) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 45061 + ... + 45539.

Almost surely, 2^21698700 is an apocalyptic number.

21698700 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 21698700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31664640).

21698700 is an abundant number, since it is smaller than the sum of its proper divisors (41630580).

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

21698700 is a wasteful number, since it uses less digits than its factorization.

21698700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 647 (or 640 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 21698700 is about 4658.1863423440. The cubic root of 21698700 is about 278.9188751945.

The spelling of 21698700 in words is "twenty-one million, six hundred ninety-eight thousand, seven hundred".