61891861432 has 8 divisors (see below), whose sum is σ = 116047240200. Its totient is φ = 30945930712.

The previous prime is 61891861403. The next prime is 61891861439. The reversal of 61891861432 is 23416819816.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61891861439) 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 as a sum of consecutive naturals, namely, 3868241332 + ... + 3868241347.

It is an arithmetic number, because the mean of its divisors is an integer number (14505905025).

Almost surely, 2^61891861432 is an apocalyptic number.

It is an amenable number.

61891861432 is a deficient number, since it is larger than the sum of its proper divisors (54155378768).

61891861432 is a wasteful number, since it uses less digits than its factorization.

61891861432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7736482685 (or 7736482681 counting only the distinct ones).

The product of its digits is 497664, while the sum is 49.

The spelling of 61891861432 in words is "sixty-one billion, eight hundred ninety-one million, eight hundred sixty-one thousand, four hundred thirty-two".