261543236 has 12 divisors (see below), whose sum is σ = 457830912. Its totient is φ = 130734408.

The previous prime is 261543221. The next prime is 261543251. The reversal of 261543236 is 632345162.

It is an interprime number because it is at equal distance from previous prime (261543221) and next prime (261543251).

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11861 + ... + 25763.

It is an arithmetic number, because the mean of its divisors is an integer number (38152576).

Almost surely, 2^261543236 is an apocalyptic number.

It is an amenable number.

261543236 is a deficient number, since it is larger than the sum of its proper divisors (196287676).

261543236 is a wasteful number, since it uses less digits than its factorization.

261543236 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18610 (or 18608 counting only the distinct ones).

The product of its digits is 25920, while the sum is 32.

The square root of 261543236 is about 16172.2984142638. The cubic root of 261543236 is about 639.5107230506.

Adding to 261543236 its reverse (632345162), we get a palindrome (893888398).

The spelling of 261543236 in words is "two hundred sixty-one million, five hundred forty-three thousand, two hundred thirty-six".