61504067509 has 2 divisors, whose sum is σ = 61504067510. Its totient is φ = 61504067508.

The previous prime is 61504067501. The next prime is 61504067561. The reversal of 61504067509 is 90576040516.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 33765165009 + 27738902500 = 183753^2 + 166550^2 .

It is a cyclic number.

It is not a de Polignac number, because 61504067509 - 2³ = 61504067501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61504067501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30752033754 + 30752033755.

It is an arithmetic number, because the mean of its divisors is an integer number (30752033755).

Almost surely, 2^61504067509 is an apocalyptic number.

It is an amenable number.

61504067509 is a deficient number, since it is larger than the sum of its proper divisors (1).

61504067509 is an equidigital number, since it uses as much as digits as its factorization.

61504067509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 226800, while the sum is 43.

The spelling of 61504067509 in words is "sixty-one billion, five hundred four million, sixty-seven thousand, five hundred nine".