20021072730061 has 4 divisors (see below), whose sum is σ = 21561155247772. Its totient is φ = 18480990212352.

The previous prime is 20021072730053. The next prime is 20021072730077. The reversal of 20021072730061 is 16003727012002.

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 8226175433161 + 11794897296900 = 2868131^2 + 3434370^2 .

It is a cyclic number.

It is not a de Polignac number, because 20021072730061 - 2³ = 20021072730053 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 (20021072760061) 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, 770041258836 + ... + 770041258861.

It is an arithmetic number, because the mean of its divisors is an integer number (5390288811943).

Almost surely, 2^{20021072730061} is an apocalyptic number.

It is an amenable number.

20021072730061 is a deficient number, since it is larger than the sum of its proper divisors (1540082517711).

20021072730061 is a wasteful number, since it uses less digits than its factorization.

20021072730061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1540082517710.

The product of its (nonzero) digits is 7056, while the sum is 31.

Adding to 20021072730061 its reverse (16003727012002), we get a palindrome (36024799742063).

The spelling of 20021072730061 in words is "twenty trillion, twenty-one billion, seventy-two million, seven hundred thirty thousand, sixty-one".