12161556 has 96 divisors (see below), whose sum is σ = 35683200. Its totient is φ = 3548160.

The previous prime is 12161533. The next prime is 12161563. The reversal of 12161556 is 65516121.

It is a happy number.

It is a super-2 number, since 2×12161556² = 295806888682272, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

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, 34276 + ... + 34628.

It is an arithmetic number, because the mean of its divisors is an integer number (371700).

Almost surely, 2^12161556 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12161556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17841600).

12161556 is an abundant number, since it is smaller than the sum of its proper divisors (23521644).

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

12161556 is a wasteful number, since it uses less digits than its factorization.

12161556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 406 (or 398 counting only the distinct ones).

The product of its digits is 1800, while the sum is 27.

The square root of 12161556 is about 3487.3422544970. The cubic root of 12161556 is about 229.9656911647.

Adding to 12161556 its reverse (65516121), we get a palindrome (77677677).

It can be divided in two parts, 1216 and 1556, that added together give a palindrome (2772).

The spelling of 12161556 in words is "twelve million, one hundred sixty-one thousand, five hundred fifty-six".