20162170981 has 2 divisors, whose sum is σ = 20162170982. Its totient is φ = 20162170980.

The previous prime is 20162170937. The next prime is 20162170991. The reversal of 20162170981 is 18907126102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19737440100 + 424730881 = 140490^2 + 20609^2 .

It is a cyclic number.

It is not a de Polignac number, because 20162170981 - 2²⁹ = 19625300069 is a prime.

It is a super-2 number, since 2×20162170981² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20162170981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20162170991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10081085490 + 10081085491.

It is an arithmetic number, because the mean of its divisors is an integer number (10081085491).

Almost surely, 2^20162170981 is an apocalyptic number.

It is an amenable number.

20162170981 is a deficient number, since it is larger than the sum of its proper divisors (1).

20162170981 is an equidigital number, since it uses as much as digits as its factorization.

20162170981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 37.

The spelling of 20162170981 in words is "twenty billion, one hundred sixty-two million, one hundred seventy thousand, nine hundred eighty-one".