12561645000 has 160 divisors (see below), whose sum is σ = 39595200480. Its totient is φ = 3319680000.

The previous prime is 12561644999. The next prime is 12561645001. The reversal of 12561645000 is 54616521.

It is an interprime number because it is at equal distance from previous prime (12561644999) and next prime (12561645001).

It is a super-3 number, since 3×12561645000³ (a number of 31 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (12561645001) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1691295 + ... + 1698705.

It is an arithmetic number, because the mean of its divisors is an integer number (247470003).

Almost surely, 2^12561645000 is an apocalyptic number.

12561645000 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 12561645000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19797600240).

12561645000 is an abundant number, since it is smaller than the sum of its proper divisors (27033555480).

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

12561645000 is a wasteful number, since it uses less digits than its factorization.

12561645000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7553 (or 7534 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 30.

The spelling of 12561645000 in words is "twelve billion, five hundred sixty-one million, six hundred forty-five thousand".