21230154 has 64 divisors (see below), whose sum is σ = 52116480. Its totient is φ = 6352560.

The previous prime is 21230141. The next prime is 21230159. The reversal of 21230154 is 45103212.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21230159) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 61009 + ... + 61355.

It is an arithmetic number, because the mean of its divisors is an integer number (814320).

Almost surely, 2^21230154 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21230154, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26058240).

21230154 is an abundant number, since it is smaller than the sum of its proper divisors (30886326).

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

21230154 is a wasteful number, since it uses less digits than its factorization.

21230154 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 472 (or 466 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 21230154 is about 4607.6191248843. The cubic root of 21230154 is about 276.8966584840.

Adding to 21230154 its reverse (45103212), we get a palindrome (66333366).

The spelling of 21230154 in words is "twenty-one million, two hundred thirty thousand, one hundred fifty-four".