61147939891 has 4 divisors (see below), whose sum is σ = 61153486192. Its totient is φ = 61142393592.

The previous prime is 61147939849. The next prime is 61147939903. The reversal of 61147939891 is 19893974116.

61147939891 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 61147939891 - 2¹⁷ = 61147808819 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61147930891) 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, 2756580 + ... + 2778673.

It is an arithmetic number, because the mean of its divisors is an integer number (15288371548).

Almost surely, 2^61147939891 is an apocalyptic number.

61147939891 is a deficient number, since it is larger than the sum of its proper divisors (5546301).

61147939891 is a wasteful number, since it uses less digits than its factorization.

61147939891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5546300.

The product of its digits is 2939328, while the sum is 58.

The spelling of 61147939891 in words is "sixty-one billion, one hundred forty-seven million, nine hundred thirty-nine thousand, eight hundred ninety-one".