261315679 has 2 divisors, whose sum is σ = 261315680. Its totient is φ = 261315678.

The previous prime is 261315559. The next prime is 261315689. The reversal of 261315679 is 976513162.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 261315679 - 2¹⁷ = 261184607 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261315689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130657839 + 130657840.

It is an arithmetic number, because the mean of its divisors is an integer number (130657840).

Almost surely, 2^261315679 is an apocalyptic number.

261315679 is a deficient number, since it is larger than the sum of its proper divisors (1).

261315679 is an equidigital number, since it uses as much as digits as its factorization.

261315679 is an evil number, because the sum of its binary digits is even.

The product of its digits is 68040, while the sum is 40.

The square root of 261315679 is about 16165.2614887604. The cubic root of 261315679 is about 639.3251994011.

The spelling of 261315679 in words is "two hundred sixty-one million, three hundred fifteen thousand, six hundred seventy-nine".