21443650 has 12 divisors (see below), whose sum is σ = 39885282. Its totient is φ = 8577440.

The previous prime is 21443629. The next prime is 21443657. The reversal of 21443650 is 5634412.

It can be written as a sum of positive squares in 3 ways, for example, as 18550249 + 2893401 = 4307^2 + 1701^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (21443657) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 214387 + ... + 214486.

Almost surely, 2^21443650 is an apocalyptic number.

21443650 is a deficient number, since it is larger than the sum of its proper divisors (18441632).

21443650 is a wasteful number, since it uses less digits than its factorization.

21443650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 428885 (or 428880 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 21443650 is about 4630.7288843118. The cubic root of 21443650 is about 277.8217462252.

The spelling of 21443650 in words is "twenty-one million, four hundred forty-three thousand, six hundred fifty".