21939360 has 48 divisors (see below), whose sum is σ = 69110496. Its totient is φ = 5850368.

The previous prime is 21939277. The next prime is 21939361. The reversal of 21939360 is 6393912.

It is a tau number, because it is divible by the number of its divisors (48).

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21939361) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22374 + ... + 23333.

It is an arithmetic number, because the mean of its divisors is an integer number (1439802).

Almost surely, 2^21939360 is an apocalyptic number.

21939360 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21939360 is an abundant number, since it is smaller than the sum of its proper divisors (47171136).

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

21939360 is a wasteful number, since it uses less digits than its factorization.

21939360 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45725 (or 45717 counting only the distinct ones).

The product of its (nonzero) digits is 8748, while the sum is 33.

The square root of 21939360 is about 4683.9470535009. The cubic root of 21939360 is about 279.9462481853.

It can be divided in two parts, 219393 and 60, that added together give a triangular number (219453 = T₆₆₂).

The spelling of 21939360 in words is "twenty-one million, nine hundred thirty-nine thousand, three hundred sixty".