21080217601 has 4 divisors (see below), whose sum is σ = 21162242052. Its totient is φ = 20998193152.

The previous prime is 21080217593. The next prime is 21080217611. The reversal of 21080217601 is 10671208012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13543373376 + 7536844225 = 116376^2 + 86815^2 .

It is a cyclic number.

It is not a de Polignac number, because 21080217601 - 2³ = 21080217593 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21080217601.

It is not an unprimeable number, because it can be changed into a prime (21080217611) 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, 41011840 + ... + 41012353.

It is an arithmetic number, because the mean of its divisors is an integer number (5290560513).

Almost surely, 2^21080217601 is an apocalyptic number.

It is an amenable number.

21080217601 is a deficient number, since it is larger than the sum of its proper divisors (82024451).

21080217601 is an equidigital number, since it uses as much as digits as its factorization.

21080217601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82024450.

The product of its (nonzero) digits is 1344, while the sum is 28.

The spelling of 21080217601 in words is "twenty-one billion, eighty million, two hundred seventeen thousand, six hundred one".