261211860 has 288 divisors, whose sum is σ = 1003871232. Its totient is φ = 53498880.

The previous prime is 261211843. The next prime is 261211879. The reversal of 261211860 is 68112162.

261211860 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 605845 + ... + 606275.

It is an arithmetic number, because the mean of its divisors is an integer number (3485664).

Almost surely, 2^261211860 is an apocalyptic number.

261211860 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 261211860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (501935616).

261211860 is an abundant number, since it is smaller than the sum of its proper divisors (742659372).

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

261211860 is a wasteful number, since it uses less digits than its factorization.

261211860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 503 (or 498 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 261211860 is about 16162.0499937353. The cubic root of 261211860 is about 639.2405216210.

The spelling of 261211860 in words is "two hundred sixty-one million, two hundred eleven thousand, eight hundred sixty".