12561000 has 128 divisors (see below), whose sum is σ = 40435200. Its totient is φ = 3244800.

The previous prime is 12560993. The next prime is 12561007. The reversal of 12561000 is 16521.

It is an interprime number because it is at equal distance from previous prime (12560993) and next prime (12561007).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is not an unprimeable number, because it can be changed into a prime (12561007) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 158961 + ... + 159039.

It is an arithmetic number, because the mean of its divisors is an integer number (315900).

Almost surely, 2^12561000 is an apocalyptic number.

12561000 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 12561000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20217600).

12561000 is an abundant number, since it is smaller than the sum of its proper divisors (27874200).

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

12561000 is a wasteful number, since it uses less digits than its factorization.

12561000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156 (or 142 counting only the distinct ones).

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 12561000 is about 3544.1501096878. The cubic root of 12561000 is about 232.4563451394.

Adding to 12561000 its reverse (16521), we get a palindrome (12577521).

The spelling of 12561000 in words is "twelve million, five hundred sixty-one thousand".