103661820 has 144 divisors (see below), whose sum is σ = 328648320. Its totient is φ = 26425728.

The previous prime is 103661819. The next prime is 103661867. The reversal of 103661820 is 28166301.

103661820 is a `hidden beast` number, since 10 + 36 + 618 + 2 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 456547 + ... + 456773.

It is an arithmetic number, because the mean of its divisors is an integer number (2282280).

Almost surely, 2^103661820 is an apocalyptic number.

103661820 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 103661820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (164324160).

103661820 is an abundant number, since it is smaller than the sum of its proper divisors (224986500).

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

103661820 is a wasteful number, since it uses less digits than its factorization.

103661820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 344 (or 339 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 103661820 is about 10181.4448876375. Note that the first 3 decimals coincide. The cubic root of 103661820 is about 469.7566568885.

The spelling of 103661820 in words is "one hundred three million, six hundred sixty-one thousand, eight hundred twenty".