21571463 has 2 divisors, whose sum is σ = 21571464. Its totient is φ = 21571462.

The previous prime is 21571439. The next prime is 21571471. The reversal of 21571463 is 36417512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21571463 - 2¹⁶ = 21505927 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21571483) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10785731 + 10785732.

It is an arithmetic number, because the mean of its divisors is an integer number (10785732).

Almost surely, 2^21571463 is an apocalyptic number.

21571463 is a deficient number, since it is larger than the sum of its proper divisors (1).

21571463 is an equidigital number, since it uses as much as digits as its factorization.

21571463 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5040, while the sum is 29.

The square root of 21571463 is about 4644.5089083777. The cubic root of 21571463 is about 278.3726305764.

Adding to 21571463 its reverse (36417512), we get a palindrome (57988975).

The spelling of 21571463 in words is "twenty-one million, five hundred seventy-one thousand, four hundred sixty-three".