261223216 has 20 divisors (see below), whose sum is σ = 507726432. Its totient is φ = 130197056.

The previous prime is 261223199. The next prime is 261223247. The reversal of 261223216 is 612322162.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20680 + ... + 30823.

Almost surely, 2^261223216 is an apocalyptic number.

It is an amenable number.

261223216 is a deficient number, since it is larger than the sum of its proper divisors (246503216).

261223216 is a wasteful number, since it uses less digits than its factorization.

261223216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51828 (or 51822 counting only the distinct ones).

The product of its digits is 1728, while the sum is 25.

The square root of 261223216 is about 16162.4013067366. The cubic root of 261223216 is about 639.2497849959.

Adding to 261223216 its reverse (612322162), we get a palindrome (873545378).

The spelling of 261223216 in words is "two hundred sixty-one million, two hundred twenty-three thousand, two hundred sixteen".