21243054 has 32 divisors (see below), whose sum is σ = 49109760. Its totient is φ = 6000192.

The previous prime is 21243049. The next prime is 21243059. The reversal of 21243054 is 45034212.

It is an interprime number because it is at equal distance from previous prime (21243049) and next prime (21243059).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a self number, because there is not a number n which added to its sum of digits gives 21243054.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21243059) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 897 + ... + 6579.

It is an arithmetic number, because the mean of its divisors is an integer number (1534680).

Almost surely, 2^21243054 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21243054, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24554880).

21243054 is an abundant number, since it is smaller than the sum of its proper divisors (27866706).

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

21243054 is a wasteful number, since it uses less digits than its factorization.

21243054 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5784.

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 21243054 is about 4609.0187675903. The cubic root of 21243054 is about 276.9527303597.

Adding to 21243054 its reverse (45034212), we get a palindrome (66277266).

The spelling of 21243054 in words is "twenty-one million, two hundred forty-three thousand, fifty-four".