21675654 has 128 divisors (see below), whose sum is σ = 64834560. Its totient is φ = 5184000.

The previous prime is 21675649. The next prime is 21675659. The reversal of 21675654 is 45657612.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21675649) and next prime (21675659).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21675659) 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 63 ways as a sum of consecutive naturals, for example, 53854 + ... + 54254.

It is an arithmetic number, because the mean of its divisors is an integer number (506520).

Almost surely, 2^21675654 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21675654, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32417280).

21675654 is an abundant number, since it is smaller than the sum of its proper divisors (43158906).

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

21675654 is a wasteful number, since it uses less digits than its factorization.

21675654 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 443 (or 437 counting only the distinct ones).

The product of its digits is 50400, while the sum is 36.

The square root of 21675654 is about 4655.7119756274. The cubic root of 21675654 is about 278.8200944467.

The spelling of 21675654 in words is "twenty-one million, six hundred seventy-five thousand, six hundred fifty-four".