20978064 has 30 divisors (see below), whose sum is σ = 58709846. Its totient is φ = 6992640.

The previous prime is 20978021. The next prime is 20978077. The reversal of 20978064 is 46087902.

It can be written as a sum of positive squares in only one way, i.e., 11614464 + 9363600 = 3408^2 + 3060^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 72697 + ... + 72984.

Almost surely, 2^20978064 is an apocalyptic number.

20978064 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20978064 is an abundant number, since it is smaller than the sum of its proper divisors (37731782).

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

20978064 is a wasteful number, since it uses less digits than its factorization.

20978064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145695 (or 145686 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 20978064 is about 4580.1816557862. The cubic root of 20978064 is about 275.7963210582.

The spelling of 20978064 in words is "twenty million, nine hundred seventy-eight thousand, sixty-four".