261493287 has 8 divisors (see below), whose sum is σ = 380353920. Its totient is φ = 158480760.

The previous prime is 261493283. The next prime is 261493307. The reversal of 261493287 is 782394162.

261493287 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 261493287 - 2² = 261493283 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261493283) 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, 3961987 + ... + 3962052.

It is an arithmetic number, because the mean of its divisors is an integer number (47544240).

Almost surely, 2^261493287 is an apocalyptic number.

261493287 is a deficient number, since it is larger than the sum of its proper divisors (118860633).

261493287 is a wasteful number, since it uses less digits than its factorization.

261493287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7924053.

The product of its digits is 145152, while the sum is 42.

The square root of 261493287 is about 16170.7540640503. The cubic root of 261493287 is about 639.4700096358.

The spelling of 261493287 in words is "two hundred sixty-one million, four hundred ninety-three thousand, two hundred eighty-seven".