261931008 has 90 divisors (see below), whose sum is σ = 708160404. Its totient is φ = 86114304.

The previous prime is 261930989. The next prime is 261931009. The reversal of 261931008 is 800139162.

It is a zygodrome in base 2.

It is not an unprimeable number, because it can be changed into a prime (261931009) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3588060 + ... + 3588132.

Almost surely, 2^261931008 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 261931008, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (354080202).

261931008 is an abundant number, since it is smaller than the sum of its proper divisors (446229396).

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

261931008 is an frugal number, since it uses more digits than its factorization.

261931008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177 (or 78 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 261931008 is about 16184.2827459236. The cubic root of 261931008 is about 639.8266197010.

The spelling of 261931008 in words is "two hundred sixty-one million, nine hundred thirty-one thousand, eight".