21155152 has 40 divisors (see below), whose sum is σ = 42854400. Its totient is φ = 10104192.

The previous prime is 21155149. The next prime is 21155159. The reversal of 21155152 is 25155112.

It is a happy number.

It is a super-2 number, since 2×21155152² = 895080912286208, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21155159) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 58749 + ... + 59107.

It is an arithmetic number, because the mean of its divisors is an integer number (1071360).

Almost surely, 2^21155152 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21155152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21427200).

21155152 is an abundant number, since it is smaller than the sum of its proper divisors (21699248).

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

21155152 is a wasteful number, since it uses less digits than its factorization.

21155152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 523 (or 517 counting only the distinct ones).

The product of its digits is 500, while the sum is 22.

The square root of 21155152 is about 4599.4730132918. The cubic root of 21155152 is about 276.5701997516.

The spelling of 21155152 in words is "twenty-one million, one hundred fifty-five thousand, one hundred fifty-two".