21246366228720 has 80 divisors (see below), whose sum is σ = 65872940766720. Its totient is φ = 5664905793792.

The previous prime is 21246366228707. The next prime is 21246366228781. The reversal of 21246366228720 is 2782266364212.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4464724 + ... + 7901043.

It is an arithmetic number, because the mean of its divisors is an integer number (823411759584).

Almost surely, 2^{21246366228720} is an apocalyptic number.

21246366228720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21246366228720 is an abundant number, since it is smaller than the sum of its proper divisors (44626574538000).

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

21246366228720 is a wasteful number, since it uses less digits than its factorization.

21246366228720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12372942 (or 12372936 counting only the distinct ones).

The product of its (nonzero) digits is 4644864, while the sum is 51.

The spelling of 21246366228720 in words is "twenty-one trillion, two hundred forty-six billion, three hundred sixty-six million, two hundred twenty-eight thousand, seven hundred twenty".