161511065100 has 288 divisors, whose sum is σ = 647350233600. Its totient is φ = 33560697600.

The previous prime is 161511065099. The next prime is 161511065137. The reversal of 161511065100 is 1560115161.

161511065100 is a `hidden beast` number, since 1 + 6 + 1 + 5 + 1 + 1 + 0 + 651 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 180535 + ... + 596334.

Almost surely, 2^161511065100 is an apocalyptic number.

161511065100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161511065100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (323675116800).

161511065100 is an abundant number, since it is smaller than the sum of its proper divisors (485839168500).

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

161511065100 is a wasteful number, since it uses less digits than its factorization.

161511065100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 776910 (or 776897 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 27.

The spelling of 161511065100 in words is "one hundred sixty-one billion, five hundred eleven million, sixty-five thousand, one hundred".