170170020021 has 4 divisors (see below), whose sum is σ = 226893360032. Its totient is φ = 113446680012.

The previous prime is 170170019989. The next prime is 170170020049. The reversal of 170170020021 is 120020071071.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 120020071071 = 3 ⋅40006690357.

It is not a de Polignac number, because 170170020021 - 2⁵ = 170170019989 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 170170020021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (170170020091) 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, 28361670001 + ... + 28361670006.

It is an arithmetic number, because the mean of its divisors is an integer number (56723340008).

Almost surely, 2^170170020021 is an apocalyptic number.

It is an amenable number.

170170020021 is a deficient number, since it is larger than the sum of its proper divisors (56723340011).

170170020021 is an equidigital number, since it uses as much as digits as its factorization.

170170020021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56723340010.

The product of its (nonzero) digits is 196, while the sum is 21.

Adding to 170170020021 its reverse (120020071071), we get a palindrome (290190091092).

The spelling of 170170020021 in words is "one hundred seventy billion, one hundred seventy million, twenty thousand, twenty-one".