261797658 has 16 divisors (see below), whose sum is σ = 523871040. Its totient is φ = 87219936.

The previous prime is 261797651. The next prime is 261797659. The reversal of 261797658 is 856797162.

It is a self number, because there is not a number n which added to its sum of digits gives 261797658.

It is not an unprimeable number, because it can be changed into a prime (261797651) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 2091 + ... + 22977.

It is an arithmetic number, because the mean of its divisors is an integer number (32741940).

Almost surely, 2^261797658 is an apocalyptic number.

261797658 is an abundant number, since it is smaller than the sum of its proper divisors (262073382).

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

261797658 is a wasteful number, since it uses less digits than its factorization.

261797658 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22981.

The product of its digits is 1270080, while the sum is 51.

The square root of 261797658 is about 16180.1624837330. The cubic root of 261797658 is about 639.7180219402.

The spelling of 261797658 in words is "two hundred sixty-one million, seven hundred ninety-seven thousand, six hundred fifty-eight".