21620701110061 has 4 divisors (see below), whose sum is σ = 21701075463900. Its totient is φ = 21540326756224.

The previous prime is 21620701109983. The next prime is 21620701110131. The reversal of 21620701110061 is 16001110702612.

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 7042622594436 + 14578078515625 = 2653794^2 + 3818125^2 .

It is a cyclic number.

It is not a de Polignac number, because 21620701110061 - 2²⁵ = 21620667555629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21620701140061) 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, 40187176516 + ... + 40187177053.

It is an arithmetic number, because the mean of its divisors is an integer number (5425268865975).

Almost surely, 2^{21620701110061} is an apocalyptic number.

It is an amenable number.

21620701110061 is a deficient number, since it is larger than the sum of its proper divisors (80374353839).

21620701110061 is an equidigital number, since it uses as much as digits as its factorization.

21620701110061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80374353838.

The product of its (nonzero) digits is 1008, while the sum is 28.

Adding to 21620701110061 its reverse (16001110702612), we get a palindrome (37621811812673).

The spelling of 21620701110061 in words is "twenty-one trillion, six hundred twenty billion, seven hundred one million, one hundred ten thousand, sixty-one".