261220658 has 8 divisors (see below), whose sum is σ = 394096428. Its totient is φ = 129855184.

The previous prime is 261220627. The next prime is 261220693. The reversal of 261220658 is 856022162.

It can be written as a sum of positive squares in 2 ways, for example, as 240033049 + 21187609 = 15493^2 + 4603^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 377141 + ... + 377832.

Almost surely, 2^261220658 is an apocalyptic number.

261220658 is a deficient number, since it is larger than the sum of its proper divisors (132875770).

261220658 is a wasteful number, since it uses less digits than its factorization.

261220658 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 755148.

The product of its (nonzero) digits is 11520, while the sum is 32.

The square root of 261220658 is about 16162.3221722623. The cubic root of 261220658 is about 639.2476983943.

The spelling of 261220658 in words is "two hundred sixty-one million, two hundred twenty thousand, six hundred fifty-eight".