18621978467 has 2 divisors, whose sum is σ = 18621978468. Its totient is φ = 18621978466.

The previous prime is 18621978461. The next prime is 18621978469. The reversal of 18621978467 is 76487912681.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18621978467 - 2¹⁰ = 18621977443 is a prime.

Together with 18621978469, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18621978461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9310989233 + 9310989234.

It is an arithmetic number, because the mean of its divisors is an integer number (9310989234).

Almost surely, 2^18621978467 is an apocalyptic number.

18621978467 is a deficient number, since it is larger than the sum of its proper divisors (1).

18621978467 is an equidigital number, since it uses as much as digits as its factorization.

18621978467 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8128512, while the sum is 59.

The spelling of 18621978467 in words is "eighteen billion, six hundred twenty-one million, nine hundred seventy-eight thousand, four hundred sixty-seven".