261651343 has 2 divisors, whose sum is σ = 261651344. Its totient is φ = 261651342.

The previous prime is 261651331. The next prime is 261651359. The reversal of 261651343 is 343156162.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 261651343 - 2¹⁷ = 261520271 is a prime.

It is a super-2 number, since 2×261651343² = 136922850587407298, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261661343) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130825671 + 130825672.

It is an arithmetic number, because the mean of its divisors is an integer number (130825672).

Almost surely, 2^261651343 is an apocalyptic number.

261651343 is a deficient number, since it is larger than the sum of its proper divisors (1).

261651343 is an equidigital number, since it uses as much as digits as its factorization.

261651343 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12960, while the sum is 31.

The square root of 261651343 is about 16175.6404200885. The cubic root of 261651343 is about 639.5988232865.

The spelling of 261651343 in words is "two hundred sixty-one million, six hundred fifty-one thousand, three hundred forty-three".