20521152 has 84 divisors (see below), whose sum is σ = 61417200. Its totient is φ = 6538752.

The previous prime is 20521147. The next prime is 20521153. The reversal of 20521152 is 25112502.

It is a super-2 number, since 2×20521152² = 842235358814208, which contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20521153) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12474 + ... + 14022.

Almost surely, 2^20521152 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 20521152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30708600).

20521152 is an abundant number, since it is smaller than the sum of its proper divisors (40896048).

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

20521152 is a wasteful number, since it uses less digits than its factorization.

20521152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1590 (or 1577 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

The square root of 20521152 is about 4530.0278144841. The cubic root of 20521152 is about 273.7792812864.

Adding to 20521152 its reverse (25112502), we get a palindrome (45633654).

The spelling of 20521152 in words is "twenty million, five hundred twenty-one thousand, one hundred fifty-two".