20521512 has 80 divisors (see below), whose sum is σ = 62726400. Its totient is φ = 6216480.

The previous prime is 20521507. The next prime is 20521519. The reversal of 20521512 is 21512502.

It is a super-2 number, since 2×20521512² = 842264909532288, which contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (20521519) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 5689 + ... + 8567.

It is an arithmetic number, because the mean of its divisors is an integer number (784080).

Almost surely, 2^20521512 is an apocalyptic number.

20521512 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20521512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31363200).

20521512 is an abundant number, since it is smaller than the sum of its proper divisors (42204888).

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

20521512 is a wasteful number, since it uses less digits than its factorization.

20521512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2908 (or 2895 counting only the distinct ones).

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

The square root of 20521512 is about 4530.0675491652. The cubic root of 20521512 is about 273.7808822356.

The spelling of 20521512 in words is "twenty million, five hundred twenty-one thousand, five hundred twelve".