21932940 has 48 divisors (see below), whose sum is σ = 61796448. Its totient is φ = 5812224.

The previous prime is 21932927. The next prime is 21932947. The reversal of 21932940 is 4923912.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 21932898 and 21932907.

It is not an unprimeable number, because it can be changed into a prime (21932947) 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 15 ways as a sum of consecutive naturals, for example, 9324 + ... + 11436.

It is an arithmetic number, because the mean of its divisors is an integer number (1287426).

Almost surely, 2^21932940 is an apocalyptic number.

21932940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21932940 is an abundant number, since it is smaller than the sum of its proper divisors (39863508).

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

21932940 is a wasteful number, since it uses less digits than its factorization.

21932940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2298 (or 2296 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 30.

The square root of 21932940 is about 4683.2616839122. The cubic root of 21932940 is about 279.9189391199.

Subtracting from 21932940 its reverse (4923912), we obtain a triangular number (17009028 = T₅₈₃₂).

The spelling of 21932940 in words is "twenty-one million, nine hundred thirty-two thousand, nine hundred forty".