20515021135320 has 128 divisors (see below), whose sum is σ = 61653736362240. Its totient is φ = 5461021063680.

The previous prime is 20515021135319. The next prime is 20515021135327. The reversal of 20515021135320 is 2353112051502.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20515021135327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 155621035 + ... + 155752805.

It is an arithmetic number, because the mean of its divisors is an integer number (481669815330).

Almost surely, 2^{20515021135320} is an apocalyptic number.

20515021135320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20515021135320 is an abundant number, since it is smaller than the sum of its proper divisors (41138715226920).

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

20515021135320 is a wasteful number, since it uses less digits than its factorization.

20515021135320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134065 (or 134061 counting only the distinct ones).

The product of its (nonzero) digits is 9000, while the sum is 30.

Adding to 20515021135320 its reverse (2353112051502), we get a palindrome (22868133186822).

The spelling of 20515021135320 in words is "twenty trillion, five hundred fifteen billion, twenty-one million, one hundred thirty-five thousand, three hundred twenty".