21789027 has 32 divisors (see below), whose sum is σ = 36288000. Its totient is φ = 12820896.

The previous prime is 21789023. The next prime is 21789037. The reversal of 21789027 is 72098712.

It is not a de Polignac number, because 21789027 - 2² = 21789023 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21788982 and 21789000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21789023) 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 31 ways as a sum of consecutive naturals, for example, 6724 + ... + 9422.

It is an arithmetic number, because the mean of its divisors is an integer number (1134000).

Almost surely, 2^21789027 is an apocalyptic number.

21789027 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

21789027 is a deficient number, since it is larger than the sum of its proper divisors (14498973).

21789027 is a wasteful number, since it uses less digits than its factorization.

21789027 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2744 (or 2738 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 36.

The square root of 21789027 is about 4667.8717848716. The cubic root of 21789027 is about 279.3053657359.

The spelling of 21789027 in words is "twenty-one million, seven hundred eighty-nine thousand, twenty-seven".