19687424705691 has 16 divisors (see below), whose sum is σ = 26303641484544. Its totient is φ = 13098099192224.

The previous prime is 19687424705671. The next prime is 19687424705801. The reversal of 19687424705691 is 19650742478691.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19687424705691 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19687424705671) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1336636 + ... + 6415718.

It is an arithmetic number, because the mean of its divisors is an integer number (1643977592784).

Almost surely, 2^{19687424705691} is an apocalyptic number.

19687424705691 is a deficient number, since it is larger than the sum of its proper divisors (6616216778853).

19687424705691 is a wasteful number, since it uses less digits than its factorization.

19687424705691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5081730.

The product of its (nonzero) digits is 182891520, while the sum is 69.

The spelling of 19687424705691 in words is "nineteen trillion, six hundred eighty-seven billion, four hundred twenty-four million, seven hundred five thousand, six hundred ninety-one".