9161820 has 72 divisors (see below), whose sum is σ = 29012256. Its totient is φ = 2335872.

The previous prime is 9161809. The next prime is 9161837. The reversal of 9161820 is 281619.

9161820 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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, 3034 + ... + 5246.

It is an arithmetic number, because the mean of its divisors is an integer number (402948).

Almost surely, 2^9161820 is an apocalyptic number.

9161820 is a gapful number since it is divisible by the number (90) 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 9161820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14506128).

9161820 is an abundant number, since it is smaller than the sum of its proper divisors (19850436).

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

9161820 is a wasteful number, since it uses less digits than its factorization.

9161820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2251 (or 2246 counting only the distinct ones).

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

The square root of 9161820 is about 3026.8498476139. The cubic root of 9161820 is about 209.2476479568.

The spelling of 9161820 in words is "nine million, one hundred sixty-one thousand, eight hundred twenty".