21135546 has 16 divisors (see below), whose sum is σ = 46968000. Its totient is φ = 7045164.

The previous prime is 21135503. The next prime is 21135553. The reversal of 21135546 is 64553112.

21135546 is a `hidden beast` number, since 2 + 113 + 5 + 546 = 666.

It is a super-2 number, since 2×21135546² = 893422609436232, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 195646 + ... + 195753.

It is an arithmetic number, because the mean of its divisors is an integer number (2935500).

Almost surely, 2^21135546 is an apocalyptic number.

21135546 is an abundant number, since it is smaller than the sum of its proper divisors (25832454).

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

21135546 is a wasteful number, since it uses less digits than its factorization.

21135546 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 391410 (or 391404 counting only the distinct ones).

The product of its digits is 3600, while the sum is 27.

The square root of 21135546 is about 4597.3411881217. The cubic root of 21135546 is about 276.4847341824.

Adding to 21135546 its reverse (64553112), we get a palindrome (85688658).

The spelling of 21135546 in words is "twenty-one million, one hundred thirty-five thousand, five hundred forty-six".