21086073 has 12 divisors (see below), whose sum is σ = 30760548. Its totient is φ = 13917600.

The previous prime is 21086027. The next prime is 21086089. The reversal of 21086073 is 37068012.

It can be written as a sum of positive squares in 2 ways, for example, as 9715689 + 11370384 = 3117^2 + 3372^2 .

It is not a de Polignac number, because 21086073 - 2¹⁶ = 21020537 is a prime.

It is a super-2 number, since 2×21086073² = 889244949122658, which contains 22 as substring.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21086003) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10690 + ... + 12507.

It is an arithmetic number, because the mean of its divisors is an integer number (2563379).

Almost surely, 2^21086073 is an apocalyptic number.

It is an amenable number.

21086073 is a deficient number, since it is larger than the sum of its proper divisors (9674475).

21086073 is a wasteful number, since it uses less digits than its factorization.

21086073 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23304 (or 23301 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 21086073 is about 4591.9574257608. The cubic root of 21086073 is about 276.2688385561.

The spelling of 21086073 in words is "twenty-one million, eighty-six thousand, seventy-three".