21420322471 has 2 divisors, whose sum is σ = 21420322472. Its totient is φ = 21420322470.

The previous prime is 21420322321. The next prime is 21420322513. The reversal of 21420322471 is 17422302412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21420322471 - 2¹⁵ = 21420289703 is a prime.

It is a super-3 number, since 3×21420322471³ (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 (21420322271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10710161235 + 10710161236.

It is an arithmetic number, because the mean of its divisors is an integer number (10710161236).

Almost surely, 2^21420322471 is an apocalyptic number.

21420322471 is a deficient number, since it is larger than the sum of its proper divisors (1).

21420322471 is an equidigital number, since it uses as much as digits as its factorization.

21420322471 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5376, while the sum is 28.

Adding to 21420322471 its reverse (17422302412), we get a palindrome (38842624883).

The spelling of 21420322471 in words is "twenty-one billion, four hundred twenty million, three hundred twenty-two thousand, four hundred seventy-one".