21540046 has 8 divisors (see below), whose sum is σ = 35247384. Its totient is φ = 9790920.

The previous prime is 21540023. The next prime is 21540049. The reversal of 21540046 is 64004512.

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

It is a Harshad number since it is a multiple of its sum of digits (22), and also a Moran number because the ratio is a prime number: 979093 = 21540046 / (2 + 1 + 5 + 4 + 0 + 0 + 4 + 6).

It is a plaindrome in base 16.

It is a junction number, because it is equal to n+sod(n) for n = 21539999 and 21540026.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21540049) 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, 489525 + ... + 489568.

It is an arithmetic number, because the mean of its divisors is an integer number (4405923).

Almost surely, 2^21540046 is an apocalyptic number.

21540046 is a deficient number, since it is larger than the sum of its proper divisors (13707338).

21540046 is a wasteful number, since it uses less digits than its factorization.

21540046 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 979106.

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 21540046 is about 4641.1255100460. The cubic root of 21540046 is about 278.2374229006.

Adding to 21540046 its reverse (64004512), we get a palindrome (85544558).

The spelling of 21540046 in words is "twenty-one million, five hundred forty thousand, forty-six".