261553895 has 8 divisors (see below), whose sum is σ = 315944160. Its totient is φ = 207856800.

The previous prime is 261553889. The next prime is 261553921. The reversal of 261553895 is 598355162.

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

It is not a de Polignac number, because 261553895 - 2⁴ = 261553879 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 172460 + ... + 173969.

It is an arithmetic number, because the mean of its divisors is an integer number (39493020).

Almost surely, 2^261553895 is an apocalyptic number.

261553895 is a deficient number, since it is larger than the sum of its proper divisors (54390265).

261553895 is a wasteful number, since it uses less digits than its factorization.

261553895 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 346585.

The product of its digits is 324000, while the sum is 44.

The square root of 261553895 is about 16172.6279559013. The cubic root of 261553895 is about 639.5194105272.

The spelling of 261553895 in words is "two hundred sixty-one million, five hundred fifty-three thousand, eight hundred ninety-five".