21961443 has 16 divisors (see below), whose sum is σ = 33580800. Its totient is φ = 12506016.

The previous prime is 21961427. The next prime is 21961453. The reversal of 21961443 is 34416912.

It is not a de Polignac number, because 21961443 - 2⁴ = 21961427 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21961443.

It is not an unprimeable number, because it can be changed into a prime (21961453) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5008 + ... + 8306.

It is an arithmetic number, because the mean of its divisors is an integer number (2098800).

Almost surely, 2^21961443 is an apocalyptic number.

21961443 is a deficient number, since it is larger than the sum of its proper divisors (11619357).

21961443 is a wasteful number, since it uses less digits than its factorization.

21961443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3626.

The product of its digits is 5184, while the sum is 30.

The square root of 21961443 is about 4686.3037673629. The cubic root of 21961443 is about 280.0401430540.

The spelling of 21961443 in words is "twenty-one million, nine hundred sixty-one thousand, four hundred forty-three".