20701517006561 has 4 divisors (see below), whose sum is σ = 21601582963392. Its totient is φ = 19801451049732.

The previous prime is 20701517006543. The next prime is 20701517006563. The reversal of 20701517006561 is 16560071510702.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20701517006561 is a prime.

It is a super-2 number, since 2×20701517006561² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20701517006563) 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, 450032978381 + ... + 450032978426.

It is an arithmetic number, because the mean of its divisors is an integer number (5400395740848).

Almost surely, 2^{20701517006561} is an apocalyptic number.

It is an amenable number.

20701517006561 is a deficient number, since it is larger than the sum of its proper divisors (900065956831).

20701517006561 is an equidigital number, since it uses as much as digits as its factorization.

20701517006561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 900065956830.

The product of its (nonzero) digits is 88200, while the sum is 41.

The spelling of 20701517006561 in words is "twenty trillion, seven hundred one billion, five hundred seventeen million, six thousand, five hundred sixty-one".