261661038 has 16 divisors (see below), whose sum is σ = 523734096. Its totient is φ = 87151680.

The previous prime is 261661033. The next prime is 261661061. The reversal of 261661038 is 830166162.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261661031) 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, 8581 + ... + 24432.

It is an arithmetic number, because the mean of its divisors is an integer number (32733381).

Almost surely, 2^261661038 is an apocalyptic number.

261661038 is an abundant number, since it is smaller than the sum of its proper divisors (262073058).

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

261661038 is a wasteful number, since it uses less digits than its factorization.

261661038 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34339.

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 261661038 is about 16175.9400963283. The cubic root of 261661038 is about 639.6067229007.

The spelling of 261661038 in words is "two hundred sixty-one million, six hundred sixty-one thousand, thirty-eight".