21073684 has 12 divisors (see below), whose sum is σ = 36911700. Its totient is φ = 10527488.

The previous prime is 21073673. The next prime is 21073699. The reversal of 21073684 is 48637012.

It can be written as a sum of positive squares in 2 ways, for example, as 11710084 + 9363600 = 3422^2 + 3060^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6162 + ... + 8950.

It is an arithmetic number, because the mean of its divisors is an integer number (3075975).

Almost surely, 2^21073684 is an apocalyptic number.

It is an amenable number.

21073684 is a deficient number, since it is larger than the sum of its proper divisors (15838016).

21073684 is a wasteful number, since it uses less digits than its factorization.

21073684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4682 (or 4680 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 21073684 is about 4590.6082385671. The cubic root of 21073684 is about 276.2147212376.

The spelling of 21073684 in words is "twenty-one million, seventy-three thousand, six hundred eighty-four".