8161920 has 192 divisors, whose sum is σ = 30630600. Its totient is φ = 1990656.

The previous prime is 8161913. The next prime is 8161931. The reversal of 8161920 is 291618.

It can be written as a sum of positive squares in 4 ways, for example, as 5875776 + 2286144 = 2424^2 + 1512^2 .

It is a tau number, because it is divible by the number of its divisors (192).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 74826 + ... + 74934.

Almost surely, 2^8161920 is an apocalyptic number.

8161920 is a gapful number since it is divisible by the number (80) 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 8161920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15315300).

8161920 is an abundant number, since it is smaller than the sum of its proper divisors (22468680).

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

8161920 is a wasteful number, since it uses less digits than its factorization.

8161920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147 (or 132 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 8161920 is about 2856.9074188710. The cubic root of 8161920 is about 201.3403308339.

It can be divided in two parts, 81 and 61920, that added together give a square (62001 = 249²).

The spelling of 8161920 in words is "eight million, one hundred sixty-one thousand, nine hundred twenty".