261561632012 has 24 divisors (see below), whose sum is σ = 464622530736. Its totient is φ = 128821690368.

The previous prime is 261561631997. The next prime is 261561632039. The reversal of 261561632012 is 210236165162.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1057013 + ... + 1280780.

It is an arithmetic number, because the mean of its divisors is an integer number (19359272114).

Almost surely, 2^261561632012 is an apocalyptic number.

It is an amenable number.

261561632012 is a deficient number, since it is larger than the sum of its proper divisors (203060898724).

261561632012 is a wasteful number, since it uses less digits than its factorization.

261561632012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2338217 (or 2338215 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 35.

Adding to 261561632012 its reverse (210236165162), we get a palindrome (471797797174).

The spelling of 261561632012 in words is "two hundred sixty-one billion, five hundred sixty-one million, six hundred thirty-two thousand, twelve".