261493870 has 32 divisors (see below), whose sum is σ = 531191520. Its totient is φ = 91808640.

The previous prime is 261493867. The next prime is 261493873. The reversal of 261493870 is 78394162.

It is an interprime number because it is at equal distance from previous prime (261493867) and next prime (261493873).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261493873) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37797 + ... + 44176.

It is an arithmetic number, because the mean of its divisors is an integer number (16599735).

Almost surely, 2^261493870 is an apocalyptic number.

261493870 is an abundant number, since it is smaller than the sum of its proper divisors (269697650).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261493870 is a wasteful number, since it uses less digits than its factorization.

261493870 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82020.

The product of its (nonzero) digits is 72576, while the sum is 40.

The square root of 261493870 is about 16170.7720904105. The cubic root of 261493870 is about 639.4704848688.

The spelling of 261493870 in words is "two hundred sixty-one million, four hundred ninety-three thousand, eight hundred seventy".