12157720 has 64 divisors (see below), whose sum is σ = 30520800. Its totient is φ = 4331520.

The previous prime is 12157711. The next prime is 12157721. The reversal of 12157720 is 2775121.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12157721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12450 + ... + 13390.

Almost surely, 2^12157720 is an apocalyptic number.

12157720 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 12157720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15260400).

12157720 is an abundant number, since it is smaller than the sum of its proper divisors (18363080).

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

12157720 is a wasteful number, since it uses less digits than its factorization.

12157720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 988 (or 984 counting only the distinct ones).

The product of its (nonzero) digits is 980, while the sum is 25.

The square root of 12157720 is about 3486.7922220861. The cubic root of 12157720 is about 229.9415100167.

The spelling of 12157720 in words is "twelve million, one hundred fifty-seven thousand, seven hundred twenty".