21521013010220 has 12 divisors (see below), whose sum is σ = 45194127321504. Its totient is φ = 8608405204080.

The previous prime is 21521013010219. The next prime is 21521013010223. The reversal of 21521013010220 is 2201031012512.

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 1076050650511 = 21521013010220 / (2 + 1 + 5 + 2 + 1 + 0 + 1 + 3 + 0 + 1 + 0 + 2 + 2 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 21521013010192 and 21521013010201.

It is not an unprimeable number, because it can be changed into a prime (21521013010223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 538025325236 + ... + 538025325275.

It is an arithmetic number, because the mean of its divisors is an integer number (3766177276792).

Almost surely, 2^{21521013010220} is an apocalyptic number.

21521013010220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21521013010220 is an abundant number, since it is smaller than the sum of its proper divisors (23673114311284).

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

21521013010220 is a wasteful number, since it uses less digits than its factorization.

21521013010220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1076050650520 (or 1076050650518 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 20.

Adding to 21521013010220 its reverse (2201031012512), we get a palindrome (23722044022732).

The spelling of 21521013010220 in words is "twenty-one trillion, five hundred twenty-one billion, thirteen million, ten thousand, two hundred twenty".