261515982 has 32 divisors (see below), whose sum is σ = 643732992. Its totient is φ = 68971104.

The previous prime is 261515959. The next prime is 261515993. The reversal of 261515982 is 289515162.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 261515982.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 238938 + ... + 240029.

It is an arithmetic number, because the mean of its divisors is an integer number (20116656).

Almost surely, 2^261515982 is an apocalyptic number.

261515982 is an abundant number, since it is smaller than the sum of its proper divisors (382217010).

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

261515982 is a wasteful number, since it uses less digits than its factorization.

261515982 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 478992.

The product of its digits is 43200, while the sum is 39.

The square root of 261515982 is about 16171.4557786243. The cubic root of 261515982 is about 639.4885089661.

The spelling of 261515982 in words is "two hundred sixty-one million, five hundred fifteen thousand, nine hundred eighty-two".