21986424 has 32 divisors (see below), whose sum is σ = 61074000. Its totient is φ = 7328736.

The previous prime is 21986417. The next prime is 21986431. The reversal of 21986424 is 42468912.

21986424 is a `hidden beast` number, since 2 + 1 + 9 + 8 + 642 + 4 = 666.

It is an interprime number because it is at equal distance from previous prime (21986417) and next prime (21986431).

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.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50679 + ... + 51110.

Almost surely, 2^21986424 is an apocalyptic number.

21986424 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21986424 is an abundant number, since it is smaller than the sum of its proper divisors (39087576).

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

21986424 is a wasteful number, since it uses less digits than its factorization.

21986424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101804 (or 101794 counting only the distinct ones).

The product of its digits is 27648, while the sum is 36.

The square root of 21986424 is about 4688.9683300274. The cubic root of 21986424 is about 280.1462841058.

The spelling of 21986424 in words is "twenty-one million, nine hundred eighty-six thousand, four hundred twenty-four".