21986470 has 16 divisors (see below), whose sum is σ = 43173648. Its totient is φ = 7995040.

The previous prime is 21986449. The next prime is 21986507. The reversal of 21986470 is 7468912.

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, 99829 + ... + 100048.

It is an arithmetic number, because the mean of its divisors is an integer number (2698353).

Almost surely, 2^21986470 is an apocalyptic number.

21986470 is a deficient number, since it is larger than the sum of its proper divisors (21187178).

21986470 is a wasteful number, since it uses less digits than its factorization.

21986470 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199895.

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 21986470 is about 4688.9732351550. The cubic root of 21986470 is about 280.1464794797.

It can be divided in two parts, 2198 and 6470, that added together give a palindrome (8668).

The spelling of 21986470 in words is "twenty-one million, nine hundred eighty-six thousand, four hundred seventy".