21486523 has 2 divisors, whose sum is σ = 21486524. Its totient is φ = 21486522.

The previous prime is 21486467. The next prime is 21486527. The reversal of 21486523 is 32568412.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21486523 is a prime.

It is not a weakly prime, because it can be changed into another prime (21486527) 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, 10743261 + 10743262.

It is an arithmetic number, because the mean of its divisors is an integer number (10743262).

Almost surely, 2^21486523 is an apocalyptic number.

21486523 is a deficient number, since it is larger than the sum of its proper divisors (1).

21486523 is an equidigital number, since it uses as much as digits as its factorization.

21486523 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11520, while the sum is 31.

The square root of 21486523 is about 4635.3557576523. The cubic root of 21486523 is about 278.0067757091.

The spelling of 21486523 in words is "twenty-one million, four hundred eighty-six thousand, five hundred twenty-three".