21245154 has 64 divisors (see below), whose sum is σ = 51916800. Its totient is φ = 5660928.

The previous prime is 21245153. The next prime is 21245167. The reversal of 21245154 is 45154212.

It is not an unprimeable number, because it can be changed into a prime (21245153) 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, 62874 + ... + 63210.

It is an arithmetic number, because the mean of its divisors is an integer number (811200).

Almost surely, 2^21245154 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21245154, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25958400).

21245154 is an abundant number, since it is smaller than the sum of its proper divisors (30671646).

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

21245154 is a wasteful number, since it uses less digits than its factorization.

21245154 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 447.

The product of its digits is 1600, while the sum is 24.

The square root of 21245154 is about 4609.2465761771. The cubic root of 21245154 is about 276.9618561908.

Adding to 21245154 its reverse (45154212), we get a palindrome (66399366).

The spelling of 21245154 in words is "twenty-one million, two hundred forty-five thousand, one hundred fifty-four".