161605501111110 has 128 divisors (see below), whose sum is σ = 458825800043520. Its totient is φ = 35642873516544.

The previous prime is 161605501111099. The next prime is 161605501111133. The reversal of 161605501111110 is 11111105506161.

It is a happy number.

It is a super-2 number, since 2×161605501111110² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1864197 + ... + 18074463.

It is an arithmetic number, because the mean of its divisors is an integer number (3584576562840).

Almost surely, 2^{161605501111110} is an apocalyptic number.

161605501111110 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 161605501111110, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (229412900021760).

161605501111110 is an abundant number, since it is smaller than the sum of its proper divisors (297220298932410).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161605501111110 is a wasteful number, since it uses less digits than its factorization.

161605501111110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16211950.

The product of its (nonzero) digits is 900, while the sum is 30.

Adding to 161605501111110 its reverse (11111105506161), we get a palindrome (172716606617271).

The spelling of 161605501111110 in words is "one hundred sixty-one trillion, six hundred five billion, five hundred one million, one hundred eleven thousand, one hundred ten".