21717418427 has 2 divisors, whose sum is σ = 21717418428. Its totient is φ = 21717418426.

The previous prime is 21717418379. The next prime is 21717418441. The reversal of 21717418427 is 72481471712.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21717418427 - 2²² = 21713224123 is a prime.

It is not a weakly prime, because it can be changed into another prime (21717418447) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10858709213 + 10858709214.

It is an arithmetic number, because the mean of its divisors is an integer number (10858709214).

Almost surely, 2^21717418427 is an apocalyptic number.

21717418427 is a deficient number, since it is larger than the sum of its proper divisors (1).

21717418427 is an equidigital number, since it uses as much as digits as its factorization.

21717418427 is an evil number, because the sum of its binary digits is even.

The product of its digits is 175616, while the sum is 44.

The spelling of 21717418427 in words is "twenty-one billion, seven hundred seventeen million, four hundred eighteen thousand, four hundred twenty-seven".