261011812 has 12 divisors (see below), whose sum is σ = 483639660. Its totient is φ = 122829056.

The previous prime is 261011809. The next prime is 261011831. The reversal of 261011812 is 218110162.

It can be written as a sum of positive squares in 2 ways, for example, as 236667456 + 24344356 = 15384^2 + 4934^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1919137 + ... + 1919272.

It is an arithmetic number, because the mean of its divisors is an integer number (40303305).

Almost surely, 2^261011812 is an apocalyptic number.

It is an amenable number.

261011812 is a deficient number, since it is larger than the sum of its proper divisors (222627848).

261011812 is a wasteful number, since it uses less digits than its factorization.

261011812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3838430 (or 3838428 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 22.

The square root of 261011812 is about 16155.8599894899. The cubic root of 261011812 is about 639.0772933932.

Adding to 261011812 its reverse (218110162), we get a palindrome (479121974).

The spelling of 261011812 in words is "two hundred sixty-one million, eleven thousand, eight hundred twelve".