21431214 has 48 divisors (see below), whose sum is σ = 54513888. Its totient is φ = 5956416.

The previous prime is 21431209. The next prime is 21431231. The reversal of 21431214 is 41213412.

21431214 is a `hidden beast` number, since 21 + 431 + 214 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

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, 2364 + ... + 6960.

It is an arithmetic number, because the mean of its divisors is an integer number (1135706).

Almost surely, 2^21431214 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21431214, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27256944).

21431214 is an abundant number, since it is smaller than the sum of its proper divisors (33082674).

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

21431214 is a wasteful number, since it uses less digits than its factorization.

21431214 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4649 (or 4646 counting only the distinct ones).

The product of its digits is 192, while the sum is 18.

The square root of 21431214 is about 4629.3859204002. The cubic root of 21431214 is about 277.7680293231.

Adding to 21431214 its reverse (41213412), we get a palindrome (62644626).

The spelling of 21431214 in words is "twenty-one million, four hundred thirty-one thousand, two hundred fourteen".