261268816 has 10 divisors (see below), whose sum is σ = 506208362. Its totient is φ = 130634400.

The previous prime is 261268793. The next prime is 261268831. The reversal of 261268816 is 618862162.

It can be written as a sum of positive squares in only one way, i.e., 176996416 + 84272400 = 13304^2 + 9180^2 .

It is a super-2 number, since 2×261268816² = 136522788428083712, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 8164635 + ... + 8164666.

Almost surely, 2^261268816 is an apocalyptic number.

It is an amenable number.

261268816 is a deficient number, since it is larger than the sum of its proper divisors (244939546).

261268816 is a wasteful number, since it uses less digits than its factorization.

261268816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16329309 (or 16329303 counting only the distinct ones).

The product of its digits is 55296, while the sum is 40.

The square root of 261268816 is about 16163.8119266465. The cubic root of 261268816 is about 639.2869793600.

The spelling of 261268816 in words is "two hundred sixty-one million, two hundred sixty-eight thousand, eight hundred sixteen".