20645064 has 64 divisors (see below), whose sum is σ = 62568000. Its totient is φ = 6255360.

The previous prime is 20645047. The next prime is 20645069. The reversal of 20645064 is 46054602.

It is a happy number.

20645064 is a `hidden beast` number, since 206 + 450 + 6 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (20645069) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1969 + ... + 6720.

It is an arithmetic number, because the mean of its divisors is an integer number (977625).

Almost surely, 2^20645064 is an apocalyptic number.

20645064 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20645064 is an abundant number, since it is smaller than the sum of its proper divisors (41922936).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20645064 is a wasteful number, since it uses less digits than its factorization.

20645064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8715 (or 8705 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

The square root of 20645064 is about 4543.6839678833. The cubic root of 20645064 is about 274.3292257980.

Adding to 20645064 its reverse (46054602), we get a palindrome (66699666).

The spelling of 20645064 in words is "twenty million, six hundred forty-five thousand, sixty-four".