61187891733509 has 2 divisors, whose sum is σ = 61187891733510. Its totient is φ = 61187891733508.

The previous prime is 61187891733503. The next prime is 61187891733511. The reversal of 61187891733509 is 90533719878116.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60874714950625 + 313176782884 = 7802225^2 + 559622^2 .

It is a cyclic number.

It is not a de Polignac number, because 61187891733509 - 2²⁴ = 61187874956293 is a prime.

Together with 61187891733511, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61187891733503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30593945866754 + 30593945866755.

It is an arithmetic number, because the mean of its divisors is an integer number (30593945866755).

Almost surely, 2^{61187891733509} is an apocalyptic number.

It is an amenable number.

61187891733509 is a deficient number, since it is larger than the sum of its proper divisors (1).

61187891733509 is an equidigital number, since it uses as much as digits as its factorization.

61187891733509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 68584320, while the sum is 68.

The spelling of 61187891733509 in words is "sixty-one trillion, one hundred eighty-seven billion, eight hundred ninety-one million, seven hundred thirty-three thousand, five hundred nine".