261436633 has 2 divisors, whose sum is σ = 261436634. Its totient is φ = 261436632.

The previous prime is 261436601. The next prime is 261436639. The reversal of 261436633 is 336634162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 205291584 + 56145049 = 14328^2 + 7493^2 .

It is a cyclic number.

It is not a de Polignac number, because 261436633 - 2⁵ = 261436601 is a prime.

It is a super-2 number, since 2×261436633² = 136698226148753378, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (261436639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130718316 + 130718317.

It is an arithmetic number, because the mean of its divisors is an integer number (130718317).

Almost surely, 2^261436633 is an apocalyptic number.

It is an amenable number.

261436633 is a deficient number, since it is larger than the sum of its proper divisors (1).

261436633 is an equidigital number, since it uses as much as digits as its factorization.

261436633 is an evil number, because the sum of its binary digits is even.

The product of its digits is 46656, while the sum is 34.

The square root of 261436633 is about 16169.0022264826. The cubic root of 261436633 is about 639.4238247018.

The spelling of 261436633 in words is "two hundred sixty-one million, four hundred thirty-six thousand, six hundred thirty-three".