21875940 has 96 divisors (see below), whose sum is σ = 72092160. Its totient is φ = 5488128.

The previous prime is 21875939. The next prime is 21875941. The reversal of 21875940 is 4957812.

It is an interprime number because it is at equal distance from previous prime (21875939) and next prime (21875941).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 21875895 and 21875904.

It is not an unprimeable number, because it can be changed into a prime (21875941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7989 + ... + 10371.

It is an arithmetic number, because the mean of its divisors is an integer number (750960).

Almost surely, 2^21875940 is an apocalyptic number.

21875940 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 21875940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36046080).

21875940 is an abundant number, since it is smaller than the sum of its proper divisors (50216220).

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

21875940 is a wasteful number, since it uses less digits than its factorization.

21875940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2418 (or 2410 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 21875940 is about 4677.1722226149. The cubic root of 21875940 is about 279.6762414348.

The spelling of 21875940 in words is "twenty-one million, eight hundred seventy-five thousand, nine hundred forty".