61394439439 has 4 divisors (see below), whose sum is σ = 62310774424. Its totient is φ = 60478104456.

The previous prime is 61394439413. The next prime is 61394439451. The reversal of 61394439439 is 93493449316.

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 61394439439 - 2¹³ = 61394431247 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 61394439439.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61394439479) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 458167392 + ... + 458167525.

It is an arithmetic number, because the mean of its divisors is an integer number (15577693606).

Almost surely, 2^61394439439 is an apocalyptic number.

61394439439 is a deficient number, since it is larger than the sum of its proper divisors (916334985).

61394439439 is an equidigital number, since it uses as much as digits as its factorization.

61394439439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 916334984.

The product of its digits is 7558272, while the sum is 55.

The spelling of 61394439439 in words is "sixty-one billion, three hundred ninety-four million, four hundred thirty-nine thousand, four hundred thirty-nine".