21881673 has 24 divisors (see below), whose sum is σ = 36298080. Its totient is φ = 12562560.

The previous prime is 21881663. The next prime is 21881681. The reversal of 21881673 is 37618812.

It is not a de Polignac number, because 21881673 - 2¹⁴ = 21865289 is a prime.

It is a super-2 number, since 2×21881673² = 957615226557858, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21881603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3936 + ... + 7697.

It is an arithmetic number, because the mean of its divisors is an integer number (1512420).

Almost surely, 2^21881673 is an apocalyptic number.

It is an amenable number.

21881673 is a deficient number, since it is larger than the sum of its proper divisors (14416407).

21881673 is a wasteful number, since it uses less digits than its factorization.

21881673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11669 (or 11666 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 21881673 is about 4677.7850527787. The cubic root of 21881673 is about 279.7006707675.

The spelling of 21881673 in words is "twenty-one million, eight hundred eighty-one thousand, six hundred seventy-three".