21768054 has 96 divisors (see below), whose sum is σ = 56733696. Its totient is φ = 5503680.

The previous prime is 21768049. The next prime is 21768059. The reversal of 21768054 is 45086712.

It is an interprime number because it is at equal distance from previous prime (21768049) and next prime (21768059).

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21768059) 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 47 ways as a sum of consecutive naturals, for example, 171339 + ... + 171465.

It is an arithmetic number, because the mean of its divisors is an integer number (590976).

Almost surely, 2^21768054 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21768054, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28366848).

21768054 is an abundant number, since it is smaller than the sum of its proper divisors (34965642).

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

21768054 is a wasteful number, since it uses less digits than its factorization.

21768054 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210 (or 203 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 33.

The square root of 21768054 is about 4665.6247170127. The cubic root of 21768054 is about 279.2157219604.

The spelling of 21768054 in words is "twenty-one million, seven hundred sixty-eight thousand, fifty-four".