261771513 has 8 divisors (see below), whose sum is σ = 352417728. Its totient is φ = 172819824.

The previous prime is 261771509. The next prime is 261771547. The reversal of 261771513 is 315177162.

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

It is not a de Polignac number, because 261771513 - 2² = 261771509 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261771553) 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, 423270 + ... + 423887.

It is an arithmetic number, because the mean of its divisors is an integer number (44052216).

Almost surely, 2^261771513 is an apocalyptic number.

It is an amenable number.

261771513 is a deficient number, since it is larger than the sum of its proper divisors (90646215).

261771513 is a wasteful number, since it uses less digits than its factorization.

261771513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 847263.

The product of its digits is 8820, while the sum is 33.

The square root of 261771513 is about 16179.3545297703. The cubic root of 261771513 is about 639.6967256146.

The spelling of 261771513 in words is "two hundred sixty-one million, seven hundred seventy-one thousand, five hundred thirteen".