12561349980 has 96 divisors (see below), whose sum is σ = 37264631040. Its totient is φ = 3150627840.

The previous prime is 12561349967. The next prime is 12561349993. The reversal of 12561349980 is 8994316521.

It is an interprime number because it is at equal distance from previous prime (12561349967) and next prime (12561349993).

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, 2170731 + ... + 2176509.

It is an arithmetic number, because the mean of its divisors is an integer number (388173240).

Almost surely, 2^12561349980 is an apocalyptic number.

12561349980 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 12561349980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18632315520).

12561349980 is an abundant number, since it is smaller than the sum of its proper divisors (24703281060).

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

12561349980 is a wasteful number, since it uses less digits than its factorization.

12561349980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7939 (or 7937 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 48.

The spelling of 12561349980 in words is "twelve billion, five hundred sixty-one million, three hundred forty-nine thousand, nine hundred eighty".