12561361634 has 32 divisors (see below), whose sum is σ = 20790604800. Its totient is φ = 5671987200.

The previous prime is 12561361613. The next prime is 12561361639. The reversal of 12561361634 is 43616316521.

It is a super-2 number, since 2×12561361634² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (12561361639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48959 + ... + 165890.

It is an arithmetic number, because the mean of its divisors is an integer number (649706400).

Almost surely, 2^12561361634 is an apocalyptic number.

12561361634 is a deficient number, since it is larger than the sum of its proper divisors (8229243166).

12561361634 is a wasteful number, since it uses less digits than its factorization.

12561361634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214946.

The product of its digits is 77760, while the sum is 38.

The spelling of 12561361634 in words is "twelve billion, five hundred sixty-one million, three hundred sixty-one thousand, six hundred thirty-four".