21135548 has 24 divisors (see below), whose sum is σ = 43730400. Its totient is φ = 8745408.

The previous prime is 21135503. The next prime is 21135553. The reversal of 21135548 is 84553112.

It is a super-2 number, since 2×21135548² = 893422778520608, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a self number, because there is not a number n which added to its sum of digits gives 21135548.

It is a congruent number.

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, 12203 + ... + 13826.

It is an arithmetic number, because the mean of its divisors is an integer number (1822100).

Almost surely, 2^21135548 is an apocalyptic number.

21135548 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21135548 is an abundant number, since it is smaller than the sum of its proper divisors (22594852).

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

21135548 is a wasteful number, since it uses less digits than its factorization.

21135548 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26069 (or 26067 counting only the distinct ones).

The product of its digits is 4800, while the sum is 29.

The square root of 21135548 is about 4597.3414056387. The cubic root of 21135548 is about 276.4847429034.

The spelling of 21135548 in words is "twenty-one million, one hundred thirty-five thousand, five hundred forty-eight".