21698712 has 128 divisors (see below), whose sum is σ = 70041600. Its totient is φ = 6096384.

The previous prime is 21698711. The next prime is 21698713. The reversal of 21698712 is 21789612.

It is an interprime number because it is at equal distance from previous prime (21698711) and next prime (21698713).

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

It is a nude number because it is divisible by every one of its digits.

Its product of digits (12096) is a multiple of the sum of its prime divisors (252).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21698711) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 170793 + ... + 170919.

It is an arithmetic number, because the mean of its divisors is an integer number (547200).

Almost surely, 2^21698712 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21698712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35020800).

21698712 is an abundant number, since it is smaller than the sum of its proper divisors (48342888).

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

21698712 is a wasteful number, since it uses less digits than its factorization.

21698712 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262 (or 252 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 21698712 is about 4658.1876303988. The cubic root of 21698712 is about 278.9189266112.

The spelling of 21698712 in words is "twenty-one million, six hundred ninety-eight thousand, seven hundred twelve".