21485687 has 2 divisors, whose sum is σ = 21485688. Its totient is φ = 21485686.

The previous prime is 21485677. The next prime is 21485689. The reversal of 21485687 is 78658412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21485687 - 2¹⁴ = 21469303 is a prime.

Together with 21485689, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21485689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10742843 + 10742844.

It is an arithmetic number, because the mean of its divisors is an integer number (10742844).

Almost surely, 2^21485687 is an apocalyptic number.

21485687 is a deficient number, since it is larger than the sum of its proper divisors (1).

21485687 is an equidigital number, since it uses as much as digits as its factorization.

21485687 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 107520, while the sum is 41.

The square root of 21485687 is about 4635.2655803093. The cubic root of 21485687 is about 278.0031700896.

The spelling of 21485687 in words is "twenty-one million, four hundred eighty-five thousand, six hundred eighty-seven".