21789546 has 16 divisors (see below), whose sum is σ = 46142784. Its totient is φ = 6835904.

The previous prime is 21789511. The next prime is 21789557. The reversal of 21789546 is 64598712.

It is a super-2 number, since 2×21789546² = 949568629772232, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21789498 and 21789507.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 106710 + ... + 106913.

It is an arithmetic number, because the mean of its divisors is an integer number (2883924).

Almost surely, 2^21789546 is an apocalyptic number.

21789546 is an abundant number, since it is smaller than the sum of its proper divisors (24353238).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21789546 is a wasteful number, since it uses less digits than its factorization.

21789546 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213645.

The product of its digits is 120960, while the sum is 42.

The square root of 21789546 is about 4667.9273773271. The cubic root of 21789546 is about 279.3075833405.

The spelling of 21789546 in words is "twenty-one million, seven hundred eighty-nine thousand, five hundred forty-six".