261563396 has 12 divisors (see below), whose sum is σ = 458097948. Its totient is φ = 130678272.

The previous prime is 261563387. The next prime is 261563447. The reversal of 261563396 is 693365162.

It can be written as a sum of positive squares in 2 ways, for example, as 199374400 + 62188996 = 14120^2 + 7886^2 .

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, 20021 + ... + 30396.

It is an arithmetic number, because the mean of its divisors is an integer number (38174829).

Almost surely, 2^261563396 is an apocalyptic number.

It is an amenable number.

261563396 is a deficient number, since it is larger than the sum of its proper divisors (196534552).

261563396 is a wasteful number, since it uses less digits than its factorization.

261563396 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51718 (or 51716 counting only the distinct ones).

The product of its digits is 174960, while the sum is 41.

The square root of 261563396 is about 16172.9216902822. The cubic root of 261563396 is about 639.5271539923.

The spelling of 261563396 in words is "two hundred sixty-one million, five hundred sixty-three thousand, three hundred ninety-six".