17678921407423 has 2 divisors, whose sum is σ = 17678921407424. Its totient is φ = 17678921407422.

The previous prime is 17678921407403. The next prime is 17678921407429. The reversal of 17678921407423 is 32470412987671.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 17678921407423 - 2²¹ = 17678919310271 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (17678921407429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8839460703711 + 8839460703712.

It is an arithmetic number, because the mean of its divisors is an integer number (8839460703712).

Almost surely, 2^{17678921407423} is an apocalyptic number.

17678921407423 is a deficient number, since it is larger than the sum of its proper divisors (1).

17678921407423 is an equidigital number, since it uses as much as digits as its factorization.

17678921407423 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 28449792, while the sum is 61.

The spelling of 17678921407423 in words is "seventeen trillion, six hundred seventy-eight billion, nine hundred twenty-one million, four hundred seven thousand, four hundred twenty-three".