261766238 has 16 divisors (see below), whose sum is σ = 430084080. Its totient is φ = 118935936.

The previous prime is 261766229. The next prime is 261766259. The reversal of 261766238 is 832667162.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 261766195 and 261766204.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 131756 + ... + 133727.

It is an arithmetic number, because the mean of its divisors is an integer number (26880255).

Almost surely, 2^261766238 is an apocalyptic number.

261766238 is a deficient number, since it is larger than the sum of its proper divisors (168317842).

261766238 is a wasteful number, since it uses less digits than its factorization.

261766238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 265531.

The product of its digits is 145152, while the sum is 41.

The square root of 261766238 is about 16179.1915125571. The cubic root of 261766238 is about 639.6924287084.

The spelling of 261766238 in words is "two hundred sixty-one million, seven hundred sixty-six thousand, two hundred thirty-eight".