21407671 has 2 divisors, whose sum is σ = 21407672. Its totient is φ = 21407670.

The previous prime is 21407669. The next prime is 21407677. The reversal of 21407671 is 17670412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21407671 - 2¹ = 21407669 is a prime.

Together with 21407669, it forms a pair of twin primes.

It is equal to p_1354096 and since 21407671 and 1354096 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21407677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10703835 + 10703836.

It is an arithmetic number, because the mean of its divisors is an integer number (10703836).

Almost surely, 2^21407671 is an apocalyptic number.

21407671 is a deficient number, since it is larger than the sum of its proper divisors (1).

21407671 is an equidigital number, since it uses as much as digits as its factorization.

21407671 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2352, while the sum is 28.

The square root of 21407671 is about 4626.8424438271. The cubic root of 21407671 is about 277.6662791562. Note that the first 3 decimals are identical.

The spelling of 21407671 in words is "twenty-one million, four hundred seven thousand, six hundred seventy-one".