261869988 has 24 divisors (see below), whose sum is σ = 612885280. Its totient is φ = 87024960.

The previous prime is 261869987. The next prime is 261870001. The reversal of 261869988 is 889968162.

It is not an unprimeable number, because it can be changed into a prime (261869987) 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, 28993 + ... + 36936.

Almost surely, 2^261869988 is an apocalyptic number.

It is an amenable number.

261869988 is an abundant number, since it is smaller than the sum of its proper divisors (351015292).

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

261869988 is a wasteful number, since it uses less digits than its factorization.

261869988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66267 (or 66265 counting only the distinct ones).

The product of its digits is 2985984, while the sum is 57.

The square root of 261869988 is about 16182.3974737985. The cubic root of 261869988 is about 639.7769307227.

The spelling of 261869988 in words is "two hundred sixty-one million, eight hundred sixty-nine thousand, nine hundred eighty-eight".