261205513619 has 2 divisors, whose sum is σ = 261205513620. Its totient is φ = 261205513618.

The previous prime is 261205513589. The next prime is 261205513627. The reversal of 261205513619 is 916315502162.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261205513619 is a prime.

It is a super-2 number, since 2×261205513619² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (261205513669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130602756809 + 130602756810.

It is an arithmetic number, because the mean of its divisors is an integer number (130602756810).

Almost surely, 2^261205513619 is an apocalyptic number.

261205513619 is a deficient number, since it is larger than the sum of its proper divisors (1).

261205513619 is an equidigital number, since it uses as much as digits as its factorization.

261205513619 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 97200, while the sum is 41.

The spelling of 261205513619 in words is "two hundred sixty-one billion, two hundred five million, five hundred thirteen thousand, six hundred nineteen".