21443090 has 8 divisors (see below), whose sum is σ = 38597580. Its totient is φ = 8577232.

The previous prime is 21443087. The next prime is 21443099. The reversal of 21443090 is 9034412.

It can be written as a sum of positive squares in 2 ways, for example, as 18156121 + 3286969 = 4261^2 + 1813^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21443090² = 919612217496200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21443099) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1072145 + ... + 1072164.

Almost surely, 2^21443090 is an apocalyptic number.

21443090 is a deficient number, since it is larger than the sum of its proper divisors (17154490).

21443090 is a wasteful number, since it uses less digits than its factorization.

21443090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2144316.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 21443090 is about 4630.6684182740. The cubic root of 21443090 is about 277.8193277698.

The spelling of 21443090 in words is "twenty-one million, four hundred forty-three thousand, ninety".