261398772 has 96 divisors (see below), whose sum is σ = 722534400. Its totient is φ = 81534816.

The previous prime is 261398759. The next prime is 261398803. The reversal of 261398772 is 277893162.

261398772 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

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, 115629 + ... + 117867.

It is an arithmetic number, because the mean of its divisors is an integer number (7526400).

Almost surely, 2^261398772 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 261398772, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (361267200).

261398772 is an abundant number, since it is smaller than the sum of its proper divisors (461135628).

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

261398772 is a wasteful number, since it uses less digits than its factorization.

261398772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2322 (or 2314 counting only the distinct ones).

The product of its digits is 254016, while the sum is 45.

The square root of 261398772 is about 16167.8313944697. The cubic root of 261398772 is about 639.3929562986.

The spelling of 261398772 in words is "two hundred sixty-one million, three hundred ninety-eight thousand, seven hundred seventy-two".