21214688 has 36 divisors (see below), whose sum is σ = 45916920. Its totient is φ = 9641280.

The previous prime is 21214673. The next prime is 21214703. The reversal of 21214688 is 88641212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21214673) and next prime (21214703).

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1133 + ... + 6611.

It is an arithmetic number, because the mean of its divisors is an integer number (1275470).

Almost surely, 2^21214688 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 21214688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22958460).

21214688 is an abundant number, since it is smaller than the sum of its proper divisors (24702232).

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

21214688 is a wasteful number, since it uses less digits than its factorization.

21214688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5511 (or 5492 counting only the distinct ones).

The product of its digits is 6144, while the sum is 32.

The square root of 21214688 is about 4605.9405119910. The cubic root of 21214688 is about 276.8294031380.

The spelling of 21214688 in words is "twenty-one million, two hundred fourteen thousand, six hundred eighty-eight".