20517012 has 72 divisors (see below), whose sum is σ = 55036800. Its totient is φ = 6431040.

The previous prime is 20516999. The next prime is 20517031. The reversal of 20517012 is 21071502.

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

It is a congruent number.

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, 58614 + ... + 58962.

It is an arithmetic number, because the mean of its divisors is an integer number (764400).

Almost surely, 2^20517012 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 20517012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27518400).

20517012 is an abundant number, since it is smaller than the sum of its proper divisors (34519788).

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

20517012 is a wasteful number, since it uses less digits than its factorization.

20517012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 453 (or 448 counting only the distinct ones).

The product of its (nonzero) digits is 140, while the sum is 18.

The square root of 20517012 is about 4529.5708405985. The cubic root of 20517012 is about 273.7608690249.

Adding to 20517012 its reverse (21071502), we get a palindrome (41588514).

The spelling of 20517012 in words is "twenty million, five hundred seventeen thousand, twelve".