21678485471 has 2 divisors, whose sum is σ = 21678485472. Its totient is φ = 21678485470.

The previous prime is 21678485447. The next prime is 21678485497. The reversal of 21678485471 is 17458487612.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21678485471 is a prime.

It is a super-3 number, since 3×21678485471³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21678485401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10839242735 + 10839242736.

It is an arithmetic number, because the mean of its divisors is an integer number (10839242736).

Almost surely, 2^21678485471 is an apocalyptic number.

21678485471 is a deficient number, since it is larger than the sum of its proper divisors (1).

21678485471 is an equidigital number, since it uses as much as digits as its factorization.

21678485471 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3010560, while the sum is 53.

The spelling of 21678485471 in words is "twenty-one billion, six hundred seventy-eight million, four hundred eighty-five thousand, four hundred seventy-one".