169781309969 has 4 divisors (see below), whose sum is σ = 171462313140. Its totient is φ = 168100306800.

The previous prime is 169781309963. The next prime is 169781309983. The reversal of 169781309969 is 969903187961.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 969903187961 = 101 ⋅9603001861.

It can be written as a sum of positive squares in 2 ways, for example, as 157144852225 + 12636457744 = 396415^2 + 112412^2 .

It is a cyclic number.

It is not a de Polignac number, because 169781309969 - 2⁸ = 169781309713 is a prime.

It is a super-2 number, since 2×169781309969² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 169781309899 and 169781309908.

It is not an unprimeable number, because it can be changed into a prime (169781309963) 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, 840501434 + ... + 840501635.

It is an arithmetic number, because the mean of its divisors is an integer number (42865578285).

Almost surely, 2^169781309969 is an apocalyptic number.

It is an amenable number.

169781309969 is a deficient number, since it is larger than the sum of its proper divisors (1681003171).

169781309969 is a wasteful number, since it uses less digits than its factorization.

169781309969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1681003170.

The product of its (nonzero) digits is 39680928, while the sum is 68.

The spelling of 169781309969 in words is "one hundred sixty-nine billion, seven hundred eighty-one million, three hundred nine thousand, nine hundred sixty-nine".