21989733 has 8 divisors (see below), whose sum is σ = 29534208. Its totient is φ = 14552544.

The previous prime is 21989701. The next prime is 21989741. The reversal of 21989733 is 33798912.

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

It is not a de Polignac number, because 21989733 - 2⁵ = 21989701 is a prime.

It is a super-2 number, since 2×21989733² = 967096714822578, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21989833) 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 7 ways as a sum of consecutive naturals, for example, 26341 + ... + 27162.

It is an arithmetic number, because the mean of its divisors is an integer number (3691776).

Almost surely, 2^21989733 is an apocalyptic number.

It is an amenable number.

21989733 is a deficient number, since it is larger than the sum of its proper divisors (7544475).

21989733 is a wasteful number, since it uses less digits than its factorization.

21989733 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53643.

The product of its digits is 81648, while the sum is 42.

The square root of 21989733 is about 4689.3211662244. The cubic root of 21989733 is about 280.1603375894.

It can be divided in two parts, 21989 and 733, that added together give a palindrome (22722).

The spelling of 21989733 in words is "twenty-one million, nine hundred eighty-nine thousand, seven hundred thirty-three".