21001152 has 56 divisors (see below), whose sum is σ = 56235600. Its totient is φ = 6916096.

The previous prime is 21001121. The next prime is 21001153. The reversal of 21001152 is 25110012.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001153) 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, 16474 + ... + 17702.

Almost surely, 2^21001152 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 21001152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28117800).

21001152 is an abundant number, since it is smaller than the sum of its proper divisors (35234448).

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

21001152 is a wasteful number, since it uses less digits than its factorization.

21001152 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1333 (or 1323 counting only the distinct ones).

The product of its (nonzero) digits is 20, while the sum is 12.

The square root of 21001152 is about 4582.7013867369. The cubic root of 21001152 is about 275.8974624358.

Adding to 21001152 its reverse (25110012), we get a palindrome (46111164).

The spelling of 21001152 in words is "twenty-one million, one thousand, one hundred fifty-two".