261216469 has 2 divisors, whose sum is σ = 261216470. Its totient is φ = 261216468.

The previous prime is 261216467. The next prime is 261216479. The reversal of 261216469 is 964612162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 230280625 + 30935844 = 15175^2 + 5562^2 .

It is a cyclic number.

It is not a de Polignac number, because 261216469 - 2¹ = 261216467 is a prime.

It is a super-2 number, since 2×261216469² = 136468087353655922, which contains 22 as substring.

Together with 261216467, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_14258692 and since 261216469 and 14258692 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261216463) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130608234 + 130608235.

It is an arithmetic number, because the mean of its divisors is an integer number (130608235).

Almost surely, 2^261216469 is an apocalyptic number.

It is an amenable number.

261216469 is a deficient number, since it is larger than the sum of its proper divisors (1).

261216469 is an equidigital number, since it uses as much as digits as its factorization.

261216469 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 37.

The square root of 261216469 is about 16162.1925802163. The cubic root of 261216469 is about 639.2442813306.

The spelling of 261216469 in words is "two hundred sixty-one million, two hundred sixteen thousand, four hundred sixty-nine".