261312012 has 72 divisors (see below), whose sum is σ = 714224784. Its totient is φ = 80078976.

The previous prime is 261311987. The next prime is 261312031. The reversal of 261312012 is 210213162.

261312012 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 131458 + ... + 133430.

Almost surely, 2^261312012 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261312012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (357112392).

261312012 is an abundant number, since it is smaller than the sum of its proper divisors (452912772).

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

261312012 is a wasteful number, since it uses less digits than its factorization.

261312012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2279 (or 2274 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 261312012 is about 16165.1480661329. The cubic root of 261312012 is about 639.3222088719.

Adding to 261312012 its reverse (210213162), we get a palindrome (471525174).

The spelling of 261312012 in words is "two hundred sixty-one million, three hundred twelve thousand, twelve".