21934540 has 12 divisors (see below), whose sum is σ = 46062576. Its totient is φ = 8773808.

The previous prime is 21934537. The next prime is 21934547. The reversal of 21934540 is 4543912.

It is a super-2 number, since 2×21934540² = 962248090023200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21934499 and 21934508.

It is not an unprimeable number, because it can be changed into a prime (21934547) 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 3 ways as a sum of consecutive naturals, for example, 548344 + ... + 548383.

It is an arithmetic number, because the mean of its divisors is an integer number (3838548).

Almost surely, 2^21934540 is an apocalyptic number.

21934540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21934540 is an abundant number, since it is smaller than the sum of its proper divisors (24128036).

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

21934540 is a wasteful number, since it uses less digits than its factorization.

21934540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1096736 (or 1096734 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 21934540 is about 4683.4325019157. The cubic root of 21934540 is about 279.9257456160.

The spelling of 21934540 in words is "twenty-one million, nine hundred thirty-four thousand, five hundred forty".