21049524 has 48 divisors (see below), whose sum is σ = 55406400. Its totient is φ = 6909408.

The previous prime is 21049517. The next prime is 21049541. The reversal of 21049524 is 42594012.

21049524 is nontrivially palindromic in base 11.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5782 + ... + 8690.

It is an arithmetic number, because the mean of its divisors is an integer number (1154300).

Almost surely, 2^21049524 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21049524, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27703200).

21049524 is an abundant number, since it is smaller than the sum of its proper divisors (34356876).

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

21049524 is a wasteful number, since it uses less digits than its factorization.

21049524 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2989 (or 2981 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 21049524 is about 4587.9760243489. The cubic root of 21049524 is about 276.1091250903.

It can be divided in two parts, 2104 and 9524, that added together give a triangular number (11628 = T₁₅₂).

The spelling of 21049524 in words is "twenty-one million, forty-nine thousand, five hundred twenty-four".