21943071 has 12 divisors (see below), whose sum is σ = 32718400. Its totient is φ = 14156640.

The previous prime is 21943069. The next prime is 21943087. The reversal of 21943071 is 17034912.

It is not a de Polignac number, because 21943071 - 2¹ = 21943069 is a prime.

It is a super-2 number, since 2×21943071² = 962996729822082, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21943001) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 39046 + ... + 39603.

Almost surely, 2^21943071 is an apocalyptic number.

21943071 is a deficient number, since it is larger than the sum of its proper divisors (10775329).

21943071 is a wasteful number, since it uses less digits than its factorization.

21943071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78686 (or 78683 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The square root of 21943071 is about 4684.3431770100. The cubic root of 21943071 is about 279.9620314162.

Adding to 21943071 its reverse (17034912), we get a palindrome (38977983).

The spelling of 21943071 in words is "twenty-one million, nine hundred forty-three thousand, seventy-one".