20664465 has 32 divisors (see below), whose sum is σ = 34940160. Its totient is φ = 10407936.

The previous prime is 20664461. The next prime is 20664473. The reversal of 20664465 is 56446602.

It is not a de Polignac number, because 20664465 - 2² = 20664461 is a prime.

It is a super-2 number, since 2×20664465² = 854040227472450, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20664461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 30369 + ... + 31041.

It is an arithmetic number, because the mean of its divisors is an integer number (1091880).

Almost surely, 2^20664465 is an apocalyptic number.

It is an amenable number.

20664465 is a deficient number, since it is larger than the sum of its proper divisors (14275695).

20664465 is a wasteful number, since it uses less digits than its factorization.

20664465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 793.

The product of its (nonzero) digits is 34560, while the sum is 33.

The square root of 20664465 is about 4545.8184081637. The cubic root of 20664465 is about 274.4151316430.

The spelling of 20664465 in words is "twenty million, six hundred sixty-four thousand, four hundred sixty-five".