21064507 has 8 divisors (see below), whose sum is σ = 22095936. Its totient is φ = 20057472.

The previous prime is 21064499. The next prime is 21064523. The reversal of 21064507 is 70546012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21064507 - 2³ = 21064499 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21064567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4318 + ... + 7795.

It is an arithmetic number, because the mean of its divisors is an integer number (2761992).

Almost surely, 2^21064507 is an apocalyptic number.

21064507 is a deficient number, since it is larger than the sum of its proper divisors (1031429).

21064507 is a wasteful number, since it uses less digits than its factorization.

21064507 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12197.

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 21064507 is about 4589.6085889758. The cubic root of 21064507 is about 276.1746208208.

The spelling of 21064507 in words is "twenty-one million, sixty-four thousand, five hundred seven".