21937380 has 48 divisors (see below), whose sum is σ = 62475840. Its totient is φ = 5749888.

The previous prime is 21937379. The next prime is 21937387. The reversal of 21937380 is 8373912.

It is not an unprimeable number, because it can be changed into a prime (21937387) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 442 + ... + 6638.

It is an arithmetic number, because the mean of its divisors is an integer number (1301580).

Almost surely, 2^21937380 is an apocalyptic number.

21937380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21937380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31237920).

21937380 is an abundant number, since it is smaller than the sum of its proper divisors (40538460).

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

21937380 is a wasteful number, since it uses less digits than its factorization.

21937380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6268 (or 6266 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 33.

The square root of 21937380 is about 4683.7356885290. The cubic root of 21937380 is about 279.9378263315.

It can be divided in two parts, 219373 and 80, that added together give a triangular number (219453 = T₆₆₂).

The spelling of 21937380 in words is "twenty-one million, nine hundred thirty-seven thousand, three hundred eighty".