61155306709 has 4 divisors (see below), whose sum is σ = 69891779104. Its totient is φ = 52418834316.

The previous prime is 61155306679. The next prime is 61155306743. The reversal of 61155306709 is 90760355116.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 61155306709 - 2⁹ = 61155306197 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61155306769) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4368236187 + ... + 4368236200.

It is an arithmetic number, because the mean of its divisors is an integer number (17472944776).

Almost surely, 2^61155306709 is an apocalyptic number.

It is an amenable number.

61155306709 is a deficient number, since it is larger than the sum of its proper divisors (8736472395).

61155306709 is an equidigital number, since it uses as much as digits as its factorization.

61155306709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8736472394.

The product of its (nonzero) digits is 170100, while the sum is 43.

The spelling of 61155306709 in words is "sixty-one billion, one hundred fifty-five million, three hundred six thousand, seven hundred nine".