21754428 has 12 divisors (see below), whose sum is σ = 50760360. Its totient is φ = 7251472.

The previous prime is 21754427. The next prime is 21754429. The reversal of 21754428 is 82445712.

It is an interprime number because it is at equal distance from previous prime (21754427) and next prime (21754429).

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21754423) 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, 906423 + ... + 906446.

It is an arithmetic number, because the mean of its divisors is an integer number (4230030).

Almost surely, 2^21754428 is an apocalyptic number.

It is an amenable number.

21754428 is an abundant number, since it is smaller than the sum of its proper divisors (29005932).

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

21754428 is a wasteful number, since it uses less digits than its factorization.

21754428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1812876 (or 1812874 counting only the distinct ones).

The product of its digits is 17920, while the sum is 33.

The square root of 21754428 is about 4664.1642338151. The cubic root of 21754428 is about 279.1574502143.

It can be divided in two parts, 217 and 54428, that added together give a palindrome (54645).

The spelling of 21754428 in words is "twenty-one million, seven hundred fifty-four thousand, four hundred twenty-eight".