261001563 has 8 divisors (see below), whose sum is σ = 348532800. Its totient is φ = 173735688.

The previous prime is 261001553. The next prime is 261001567. The reversal of 261001563 is 365100162.

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

It is not a de Polignac number, because 261001563 - 2⁴ = 261001547 is a prime.

It is a super-3 number, since 3×261001563³ (a number of 26 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (261001567) 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, 64033 + ... + 67986.

It is an arithmetic number, because the mean of its divisors is an integer number (43566600).

Almost surely, 2^261001563 is an apocalyptic number.

261001563 is a deficient number, since it is larger than the sum of its proper divisors (87531237).

261001563 is a wasteful number, since it uses less digits than its factorization.

261001563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132681.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 261001563 is about 16155.5427949667. The cubic root of 261001563 is about 639.0689285242.

The spelling of 261001563 in words is "two hundred sixty-one million, one thousand, five hundred sixty-three".