161690880 has 288 divisors, whose sum is σ = 576898560. Its totient is φ = 38338560.

The previous prime is 161690873. The next prime is 161690887. The reversal of 161690880 is 88096161.

It is an interprime number because it is at equal distance from previous prime (161690873) and next prime (161690887).

It is a super-2 number, since 2×161690880² = 52287881350348800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161690887) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2046681 + ... + 2046759.

It is an arithmetic number, because the mean of its divisors is an integer number (2003120).

Almost surely, 2^161690880 is an apocalyptic number.

161690880 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 161690880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (288449280).

161690880 is an abundant number, since it is smaller than the sum of its proper divisors (415207680).

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

161690880 is a wasteful number, since it uses less digits than its factorization.

161690880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157 (or 143 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 39.

The square root of 161690880 is about 12715.7728825266. The cubic root of 161690880 is about 544.7892235465.

The spelling of 161690880 in words is "one hundred sixty-one million, six hundred ninety thousand, eight hundred eighty".