21470591 has 2 divisors, whose sum is σ = 21470592. Its totient is φ = 21470590.

The previous prime is 21470567. The next prime is 21470623. The reversal of 21470591 is 19507412.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21470591 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 (21470521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10735295 + 10735296.

It is an arithmetic number, because the mean of its divisors is an integer number (10735296).

Almost surely, 2^21470591 is an apocalyptic number.

21470591 is a deficient number, since it is larger than the sum of its proper divisors (1).

21470591 is an equidigital number, since it uses as much as digits as its factorization.

21470591 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2520, while the sum is 29.

The square root of 21470591 is about 4633.6369085201. The cubic root of 21470591 is about 277.9380458184.

The spelling of 21470591 in words is "twenty-one million, four hundred seventy thousand, five hundred ninety-one".