161529071209920 has 840 divisors, whose sum is σ = 625983489191808. Its totient is φ = 39490907443200.

The previous prime is 161529071209861. The next prime is 161529071209927. The reversal of 161529071209920 is 29902170925161.

It is a happy number.

161529071209920 is a `hidden beast` number, since 1 + 6 + 1 + 529 + 0 + 7 + 1 + 2 + 0 + 99 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161529071209927) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 289792290 + ... + 290349150.

Almost surely, 2^{161529071209920} is an apocalyptic number.

161529071209920 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 161529071209920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (312991744595904).

161529071209920 is an abundant number, since it is smaller than the sum of its proper divisors (464454417981888).

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

161529071209920 is a wasteful number, since it uses less digits than its factorization.

161529071209920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 556959 (or 556921 counting only the distinct ones).

The product of its (nonzero) digits is 1224720, while the sum is 54.

The spelling of 161529071209920 in words is "one hundred sixty-one trillion, five hundred twenty-nine billion, seventy-one million, two hundred nine thousand, nine hundred twenty".