261111960 has 96 divisors (see below), whose sum is σ = 871593840. Its totient is φ = 67744512.

The previous prime is 261111947. The next prime is 261111979. The reversal of 261111960 is 69111162.

It is a congruent number.

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, 3519 + ... + 23121.

Almost surely, 2^261111960 is an apocalyptic number.

261111960 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261111960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (435796920).

261111960 is an abundant number, since it is smaller than the sum of its proper divisors (610481880).

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

261111960 is a wasteful number, since it uses less digits than its factorization.

261111960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19657 (or 19650 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The square root of 261111960 is about 16158.9591248942. The cubic root of 261111960 is about 639.1590191056.

The spelling of 261111960 in words is "two hundred sixty-one million, one hundred eleven thousand, nine hundred sixty".