61721440199 has 4 divisors (see below), whose sum is σ = 61724343240. Its totient is φ = 61718537160.

The previous prime is 61721440181. The next prime is 61721440211. The reversal of 61721440199 is 99104412716.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61721440199 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61721440699) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1419392 + ... + 1462229.

It is an arithmetic number, because the mean of its divisors is an integer number (15431085810).

Almost surely, 2^61721440199 is an apocalyptic number.

61721440199 is a deficient number, since it is larger than the sum of its proper divisors (2903041).

61721440199 is a wasteful number, since it uses less digits than its factorization.

61721440199 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2903040.

The product of its (nonzero) digits is 108864, while the sum is 44.

The spelling of 61721440199 in words is "sixty-one billion, seven hundred twenty-one million, four hundred forty thousand, one hundred ninety-nine".