20706352081 has 2 divisors, whose sum is σ = 20706352082. Its totient is φ = 20706352080.

The previous prime is 20706352061. The next prime is 20706352091. The reversal of 20706352081 is 18025360702.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16754972481 + 3951379600 = 129441^2 + 62860^2 .

It is a cyclic number.

It is not a de Polignac number, because 20706352081 - 2⁹ = 20706351569 is a prime.

It is a super-2 number, since 2×20706352081² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20706352061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10353176040 + 10353176041.

It is an arithmetic number, because the mean of its divisors is an integer number (10353176041).

Almost surely, 2^20706352081 is an apocalyptic number.

It is an amenable number.

20706352081 is a deficient number, since it is larger than the sum of its proper divisors (1).

20706352081 is an equidigital number, since it uses as much as digits as its factorization.

20706352081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20160, while the sum is 34.

The spelling of 20706352081 in words is "twenty billion, seven hundred six million, three hundred fifty-two thousand, eighty-one".