21540022 has 8 divisors (see below), whose sum is σ = 36925776. Its totient is φ = 9231432.

The previous prime is 21540019. The next prime is 21540023. The reversal of 21540022 is 22004512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 21539978 and 21540005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21540023) 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, 769273 + ... + 769300.

It is an arithmetic number, because the mean of its divisors is an integer number (4615722).

Almost surely, 2^21540022 is an apocalyptic number.

21540022 is a deficient number, since it is larger than the sum of its proper divisors (15385754).

21540022 is a wasteful number, since it uses less digits than its factorization.

21540022 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1538582.

The product of its (nonzero) digits is 160, while the sum is 16.

The square root of 21540022 is about 4641.1229244656. The cubic root of 21540022 is about 278.2373195628.

Adding to 21540022 its reverse (22004512), we get a palindrome (43544534).

The spelling of 21540022 in words is "twenty-one million, five hundred forty thousand, twenty-two".