61644942719 has 4 divisors (see below), whose sum is σ = 61673791344. Its totient is φ = 61616094096.

The previous prime is 61644942703. The next prime is 61644942743. The reversal of 61644942719 is 91724944616.

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 61644942719 - 2⁴ = 61644942703 is a prime.

It is a super-2 number, since 2×61644942719² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61649942719) 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, 14421107 + ... + 14425380.

It is an arithmetic number, because the mean of its divisors is an integer number (15418447836).

Almost surely, 2^61644942719 is an apocalyptic number.

61644942719 is a deficient number, since it is larger than the sum of its proper divisors (28848625).

61644942719 is a wasteful number, since it uses less digits than its factorization.

61644942719 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28848624.

The product of its digits is 2612736, while the sum is 53.

The spelling of 61644942719 in words is "sixty-one billion, six hundred forty-four million, nine hundred forty-two thousand, seven hundred nineteen".