19739220056639 has 4 divisors (see below), whose sum is σ = 20900350648224. Its totient is φ = 18578089465056.

The previous prime is 19739220056513. The next prime is 19739220056651. The reversal of 19739220056639 is 93665002293791.

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-19739220056639 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19739220052639) 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, 580565295767 + ... + 580565295800.

It is an arithmetic number, because the mean of its divisors is an integer number (5225087662056).

Almost surely, 2^{19739220056639} is an apocalyptic number.

19739220056639 is a deficient number, since it is larger than the sum of its proper divisors (1161130591585).

19739220056639 is a wasteful number, since it uses less digits than its factorization.

19739220056639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1161130591584.

The product of its (nonzero) digits is 33067440, while the sum is 62.

The spelling of 19739220056639 in words is "nineteen trillion, seven hundred thirty-nine billion, two hundred twenty million, fifty-six thousand, six hundred thirty-nine".