261211872 has 48 divisors (see below), whose sum is σ = 690720912. Its totient is φ = 86430720.

The previous prime is 261211843. The next prime is 261211879. The reversal of 261211872 is 278112162.

261211872 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261211879) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3222 + ... + 23082.

It is an arithmetic number, because the mean of its divisors is an integer number (14390019).

Almost surely, 2^261211872 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 261211872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (345360456).

261211872 is an abundant number, since it is smaller than the sum of its proper divisors (429509040).

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

261211872 is a wasteful number, since it uses less digits than its factorization.

261211872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20011 (or 20003 counting only the distinct ones).

The product of its digits is 2688, while the sum is 30.

The square root of 261211872 is about 16162.0503649754. The cubic root of 261211872 is about 639.2405314098.

The spelling of 261211872 in words is "two hundred sixty-one million, two hundred eleven thousand, eight hundred seventy-two".