261006438 has 192 divisors, whose sum is σ = 720990720. Its totient is φ = 62610240.

The previous prime is 261006407. The next prime is 261006443. The reversal of 261006438 is 834600162.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

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, 9000208 + ... + 9000236.

It is an arithmetic number, because the mean of its divisors is an integer number (3755160).

Almost surely, 2^261006438 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261006438, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (360495360).

261006438 is an abundant number, since it is smaller than the sum of its proper divisors (459984282).

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

261006438 is a wasteful number, since it uses less digits than its factorization.

261006438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104 (or 75 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 30.

The square root of 261006438 is about 16155.6936712727. The cubic root of 261006438 is about 639.0729073530.

The spelling of 261006438 in words is "two hundred sixty-one million, six thousand, four hundred thirty-eight".