21480671 has 2 divisors, whose sum is σ = 21480672. Its totient is φ = 21480670.

The previous prime is 21480647. The next prime is 21480691. The reversal of 21480671 is 17608412.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21480671 is a prime.

It is a super-2 number, since 2×21480671² = 922838453220482, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21480611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10740335 + 10740336.

It is an arithmetic number, because the mean of its divisors is an integer number (10740336).

Almost surely, 2^21480671 is an apocalyptic number.

21480671 is a deficient number, since it is larger than the sum of its proper divisors (1).

21480671 is an equidigital number, since it uses as much as digits as its factorization.

21480671 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 21480671 is about 4634.7244794054. The cubic root of 21480671 is about 277.9815344083.

The spelling of 21480671 in words is "twenty-one million, four hundred eighty thousand, six hundred seventy-one".