21049744 has 45 divisors (see below), whose sum is σ = 43311681. Its totient is φ = 9910080.

The previous prime is 21049729. The next prime is 21049759. The reversal of 21049744 is 44794012.

The square root of 21049744 is 4588.

It is a perfect power (a square), and thus also a powerful number.

It is an interprime number because it is at equal distance from previous prime (21049729) and next prime (21049759).

It can be written as a sum of positive squares in only one way, i.e., 18835600 + 2214144 = 4340^2 + 1488^2 .

It is a Harshad number since it is a multiple of its sum of digits (31).

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 568894 + ... + 568930.

Almost surely, 2^21049744 is an apocalyptic number.

21049744 is the 4588-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21049744

21049744 is an abundant number, since it is smaller than the sum of its proper divisors (22261937).

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

21049744 is an equidigital number, since it uses as much as digits as its factorization.

21049744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144 (or 70 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 31.

The cubic root of 21049744 is about 276.1100870091.

The spelling of 21049744 in words is "twenty-one million, forty-nine thousand, seven hundred forty-four".