261405936 has 120 divisors (see below), whose sum is σ = 802698624. Its totient is φ = 78756480.

The previous prime is 261405887. The next prime is 261405943. The reversal of 261405936 is 639504162.

It is a happy number.

261405936 is a `hidden beast` number, since 2 + 61 + 4 + 0 + 593 + 6 = 666.

261405936 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 261405936.

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, 359205 + ... + 359931.

Almost surely, 2^261405936 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 261405936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (401349312).

261405936 is an abundant number, since it is smaller than the sum of its proper divisors (541292688).

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

261405936 is a wasteful number, since it uses less digits than its factorization.

261405936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 979 (or 970 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The square root of 261405936 is about 16168.0529440004. The cubic root of 261405936 is about 639.3987973989.

The spelling of 261405936 in words is "two hundred sixty-one million, four hundred five thousand, nine hundred thirty-six".