261796649 has 16 divisors (see below), whose sum is σ = 289111680. Its totient is φ = 235952640.

The previous prime is 261796597. The next prime is 261796663. The reversal of 261796649 is 946697162.

It is not a de Polignac number, because 261796649 - 2²⁴ = 245019433 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 261796597 and 261796606.

It is not an unprimeable number, because it can be changed into a prime (261796679) 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, 84569 + ... + 87609.

It is an arithmetic number, because the mean of its divisors is an integer number (18069480).

Almost surely, 2^261796649 is an apocalyptic number.

It is an amenable number.

261796649 is a deficient number, since it is larger than the sum of its proper divisors (27315031).

261796649 is a wasteful number, since it uses less digits than its factorization.

261796649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3280.

The product of its digits is 979776, while the sum is 50.

The square root of 261796649 is about 16180.1313035463. The cubic root of 261796649 is about 639.7172000888.

The spelling of 261796649 in words is "two hundred sixty-one million, seven hundred ninety-six thousand, six hundred forty-nine".