21789654 has 8 divisors (see below), whose sum is σ = 43579320. Its totient is φ = 7263216.

The previous prime is 21789653. The next prime is 21789661. The reversal of 21789654 is 45698712.

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

21789654 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21789653) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1815799 + ... + 1815810.

It is an arithmetic number, because the mean of its divisors is an integer number (5447415).

Almost surely, 2^21789654 is an apocalyptic number.

21789654 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21789654 is a wasteful number, since it uses less digits than its factorization.

21789654 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3631614.

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

The square root of 21789654 is about 4667.9389456161. The cubic root of 21789654 is about 279.3080448029.

The spelling of 21789654 in words is "twenty-one million, seven hundred eighty-nine thousand, six hundred fifty-four".