21642014417 has 2 divisors, whose sum is σ = 21642014418. Its totient is φ = 21642014416.

The previous prime is 21642014393. The next prime is 21642014437. The reversal of 21642014417 is 71441024612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19882128016 + 1759886401 = 141004^2 + 41951^2 .

It is a cyclic number.

It is not a de Polignac number, because 21642014417 - 2³² = 17347047121 is a prime.

It is not a weakly prime, because it can be changed into another prime (21642014437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10821007208 + 10821007209.

It is an arithmetic number, because the mean of its divisors is an integer number (10821007209).

Almost surely, 2^21642014417 is an apocalyptic number.

It is an amenable number.

21642014417 is a deficient number, since it is larger than the sum of its proper divisors (1).

21642014417 is an equidigital number, since it uses as much as digits as its factorization.

21642014417 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10752, while the sum is 32.

The spelling of 21642014417 in words is "twenty-one billion, six hundred forty-two million, fourteen thousand, four hundred seventeen".