61239772891 has 8 divisors (see below), whose sum is σ = 66836443824. Its totient is φ = 55648005120.

The previous prime is 61239772871. The next prime is 61239772897. The reversal of 61239772891 is 19827793216.

It is a happy number.

61239772891 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 61239772891 - 2¹¹ = 61239770843 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61239772897) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1199646 + ... + 1249651.

It is an arithmetic number, because the mean of its divisors is an integer number (8354555478).

Almost surely, 2^61239772891 is an apocalyptic number.

61239772891 is a deficient number, since it is larger than the sum of its proper divisors (5596670933).

61239772891 is a wasteful number, since it uses less digits than its factorization.

61239772891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2451581.

The product of its digits is 2286144, while the sum is 55.

The spelling of 61239772891 in words is "sixty-one billion, two hundred thirty-nine million, seven hundred seventy-two thousand, eight hundred ninety-one".