261797949 has 12 divisors (see below), whose sum is σ = 432174496. Its totient is φ = 149598792.

The previous prime is 261797947. The next prime is 261797989. The reversal of 261797949 is 949797162.

It is not a de Polignac number, because 261797949 - 2¹ = 261797947 is a prime.

It is a super-2 number, since 2×261797949² = 137076332201213202, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 261797895 and 261797904.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261797947) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 2077699 + ... + 2077824.

Almost surely, 2^261797949 is an apocalyptic number.

It is an amenable number.

261797949 is a deficient number, since it is larger than the sum of its proper divisors (170376547).

261797949 is a wasteful number, since it uses less digits than its factorization.

261797949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4155536 (or 4155533 counting only the distinct ones).

The product of its digits is 1714608, while the sum is 54.

The square root of 261797949 is about 16180.1714762236. The cubic root of 261797949 is about 639.7182589653.

The spelling of 261797949 in words is "two hundred sixty-one million, seven hundred ninety-seven thousand, nine hundred forty-nine".