21307698 has 48 divisors (see below), whose sum is σ = 50712480. Its totient is φ = 6682176.

The previous prime is 21307687. The next prime is 21307753. The reversal of 21307698 is 89670312.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6973 + ... + 9551.

It is an arithmetic number, because the mean of its divisors is an integer number (1056510).

Almost surely, 2^21307698 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21307698, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25356240).

21307698 is an abundant number, since it is smaller than the sum of its proper divisors (29404782).

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

21307698 is a wasteful number, since it uses less digits than its factorization.

21307698 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2613 (or 2601 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 21307698 is about 4616.0262130971. The cubic root of 21307698 is about 277.2333742916.

The spelling of 21307698 in words is "twenty-one million, three hundred seven thousand, six hundred ninety-eight".