11957820 has 96 divisors (see below), whose sum is σ = 38900736. Its totient is φ = 2688000.

The previous prime is 11957809. The next prime is 11957833. The reversal of 11957820 is 2875911.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 29620 + ... + 30020.

It is an arithmetic number, because the mean of its divisors is an integer number (405216).

Almost surely, 2^11957820 is an apocalyptic number.

11957820 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 11957820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19450368).

11957820 is an abundant number, since it is smaller than the sum of its proper divisors (26942916).

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

11957820 is a wasteful number, since it uses less digits than its factorization.

11957820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 491 (or 489 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 33.

The square root of 11957820 is about 3458.0080971565. The cubic root of 11957820 is about 228.6742888979.

The spelling of 11957820 in words is "eleven million, nine hundred fifty-seven thousand, eight hundred twenty".