21725154 has 48 divisors (see below), whose sum is σ = 51858144. Its totient is φ = 6518400.

The previous prime is 21725149. The next prime is 21725161. The reversal of 21725154 is 45152712.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21889 + ... + 22859.

It is an arithmetic number, because the mean of its divisors is an integer number (1080378).

Almost surely, 2^21725154 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21725154, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25929072).

21725154 is an abundant number, since it is smaller than the sum of its proper divisors (30132990).

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

21725154 is a wasteful number, since it uses less digits than its factorization.

21725154 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1103 (or 1100 counting only the distinct ones).

The product of its digits is 2800, while the sum is 27.

The square root of 21725154 is about 4661.0249945693. The cubic root of 21725154 is about 279.0321772731.

Adding to 21725154 its reverse (45152712), we get a palindrome (66877866).

The spelling of 21725154 in words is "twenty-one million, seven hundred twenty-five thousand, one hundred fifty-four".