161619840 has 256 divisors, whose sum is σ = 587520000. Its totient is φ = 41969664.

The previous prime is 161619839. The next prime is 161619851. The reversal of 161619840 is 48916161.

It is a happy number.

It is a super-2 number, since 2×161619840² = 52241945363251200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 161619795 and 161619804.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 812061 + ... + 812259.

It is an arithmetic number, because the mean of its divisors is an integer number (2295000).

Almost surely, 2^161619840 is an apocalyptic number.

161619840 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 161619840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (293760000).

161619840 is an abundant number, since it is smaller than the sum of its proper divisors (425900160).

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

161619840 is a wasteful number, since it uses less digits than its factorization.

161619840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 274 (or 256 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 161619840 is about 12712.9791945083. The cubic root of 161619840 is about 544.7094262283.

The spelling of 161619840 in words is "one hundred sixty-one million, six hundred nineteen thousand, eight hundred forty".