161662811309 has 8 divisors (see below), whose sum is σ = 172614691392. Its totient is φ = 151037853120.

The previous prime is 161662811257. The next prime is 161662811351. The reversal of 161662811309 is 903118266161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 161662811309 - 2⁸ = 161662811053 is a prime.

It is a super-2 number, since 2×161662811309² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 161662811309.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161662811389) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 81729452 + ... + 81731429.

It is an arithmetic number, because the mean of its divisors is an integer number (21576836424).

Almost surely, 2^161662811309 is an apocalyptic number.

It is an amenable number.

161662811309 is a deficient number, since it is larger than the sum of its proper divisors (10951880083).

161662811309 is a wasteful number, since it uses less digits than its factorization.

161662811309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163460947.

The product of its (nonzero) digits is 93312, while the sum is 44.

The spelling of 161662811309 in words is "one hundred sixty-one billion, six hundred sixty-two million, eight hundred eleven thousand, three hundred nine".