11661820 has 24 divisors (see below), whose sum is σ = 25779600. Its totient is φ = 4419072.

The previous prime is 11661773. The next prime is 11661827. The reversal of 11661820 is 2816611.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11661827) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14965 + ... + 15724.

It is an arithmetic number, because the mean of its divisors is an integer number (1074150).

Almost surely, 2^11661820 is an apocalyptic number.

11661820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

11661820 is an abundant number, since it is smaller than the sum of its proper divisors (14117780).

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

11661820 is a wasteful number, since it uses less digits than its factorization.

11661820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30717 (or 30715 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 11661820 is about 3414.9407022670. The cubic root of 11661820 is about 226.7716593565.

The spelling of 11661820 in words is "eleven million, six hundred sixty-one thousand, eight hundred twenty".