21794540 has 24 divisors (see below), whose sum is σ = 46040400. Its totient is φ = 8666048.

The previous prime is 21794533. The next prime is 21794543. The reversal of 21794540 is 4549712.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21794497 and 21794506.

It is not an unprimeable number, because it can be changed into a prime (21794543) 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 7 ways as a sum of consecutive naturals, for example, 311 + ... + 6609.

It is an arithmetic number, because the mean of its divisors is an integer number (1918350).

Almost surely, 2^21794540 is an apocalyptic number.

21794540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21794540 is an abundant number, since it is smaller than the sum of its proper divisors (24245860).

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

21794540 is a wasteful number, since it uses less digits than its factorization.

21794540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6481 (or 6479 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 21794540 is about 4668.4622735972. The cubic root of 21794540 is about 279.3289201093.

The spelling of 21794540 in words is "twenty-one million, seven hundred ninety-four thousand, five hundred forty".