261917442 has 32 divisors (see below), whose sum is σ = 587813760. Its totient is φ = 86439600.

The previous prime is 261917437. The next prime is 261917443. The reversal of 261917442 is 244719162.

It is a happy number.

261917442 is a `hidden beast` number, since 26 + 191 + 7 + 442 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 261917397 and 261917406.

It is not an unprimeable number, because it can be changed into a prime (261917443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18558 + ... + 29465.

It is an arithmetic number, because the mean of its divisors is an integer number (18369180).

Almost surely, 2^261917442 is an apocalyptic number.

261917442 is an abundant number, since it is smaller than the sum of its proper divisors (325896318).

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

261917442 is a wasteful number, since it uses less digits than its factorization.

261917442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48135 (or 48129 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 261917442 is about 16183.8636301719. The cubic root of 261917442 is about 639.8155734872.

It can be divided in two parts, 26191 and 7442, that added together give a palindrome (33633).

The spelling of 261917442 in words is "two hundred sixty-one million, nine hundred seventeen thousand, four hundred forty-two".