21849744 has 40 divisors (see below), whose sum is σ = 64509760. Its totient is φ = 6242688.

The previous prime is 21849739. The next prime is 21849749. The reversal of 21849744 is 44794812.

It is an interprime number because it is at equal distance from previous prime (21849739) and next prime (21849749).

It is a super-2 number, since 2×21849744² = 954822625731072, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21849749) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32179 + ... + 32850.

It is an arithmetic number, because the mean of its divisors is an integer number (1612744).

Almost surely, 2^21849744 is an apocalyptic number.

21849744 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21849744 is an abundant number, since it is smaller than the sum of its proper divisors (42660016).

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

21849744 is a wasteful number, since it uses less digits than its factorization.

21849744 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65047 (or 65041 counting only the distinct ones).

The product of its digits is 64512, while the sum is 39.

The square root of 21849744 is about 4674.3709737247. The cubic root of 21849744 is about 279.5645612788.

The spelling of 21849744 in words is "twenty-one million, eight hundred forty-nine thousand, seven hundred forty-four".