21840074 has 16 divisors (see below), whose sum is σ = 34450920. Its totient is φ = 10368960.

The previous prime is 21840061. The next prime is 21840079. The reversal of 21840074 is 47004812.

It can be written as a sum of positive squares in 4 ways, for example, as 5784025 + 16056049 = 2405^2 + 4007^2 .

It is not an unprimeable number, because it can be changed into a prime (21840079) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 452 + ... + 6624.

Almost surely, 2^21840074 is an apocalyptic number.

21840074 is a deficient number, since it is larger than the sum of its proper divisors (12610846).

21840074 is a wasteful number, since it uses less digits than its factorization.

21840074 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6265.

The product of its (nonzero) digits is 1792, while the sum is 26.

The square root of 21840074 is about 4673.3364954816. The cubic root of 21840074 is about 279.5233130730.

Adding to 21840074 its reverse (47004812), we get a palindrome (68844886).

The spelling of 21840074 in words is "twenty-one million, eight hundred forty thousand, seventy-four".