61308787081 has 4 divisors (see below), whose sum is σ = 61344874000. Its totient is φ = 61272700164.

The previous prime is 61308787061. The next prime is 61308787087. The reversal of 61308787081 is 18078780316.

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 61308787081 - 2¹⁵ = 61308754313 is a prime.

It is a super-2 number, since 2×61308787081² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61308787087) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18040911 + ... + 18044308.

It is an arithmetic number, because the mean of its divisors is an integer number (15336218500).

Almost surely, 2^61308787081 is an apocalyptic number.

It is an amenable number.

61308787081 is a deficient number, since it is larger than the sum of its proper divisors (36086919).

61308787081 is a wasteful number, since it uses less digits than its factorization.

61308787081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36086918.

The product of its (nonzero) digits is 451584, while the sum is 49.

The spelling of 61308787081 in words is "sixty-one billion, three hundred eight million, seven hundred eighty-seven thousand, eighty-one".