21934040 has 16 divisors (see below), whose sum is σ = 49351680. Its totient is φ = 8773600.

The previous prime is 21934039. The next prime is 21934049. The reversal of 21934040 is 4043912.

It is a super-2 number, since 2×21934040² = 962204221443200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21933997 and 21934015.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21934049) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 274136 + ... + 274215.

It is an arithmetic number, because the mean of its divisors is an integer number (3084480).

Almost surely, 2^21934040 is an apocalyptic number.

21934040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21934040 is an abundant number, since it is smaller than the sum of its proper divisors (27417640).

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

21934040 is a wasteful number, since it uses less digits than its factorization.

21934040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 548362 (or 548358 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 21934040 is about 4683.3791219588. The cubic root of 21934040 is about 279.9236186216.

Adding to 21934040 its reverse (4043912), we get a palindrome (25977952).

The spelling of 21934040 in words is "twenty-one million, nine hundred thirty-four thousand, forty".