20664020240 has 20 divisors (see below), whose sum is σ = 48043847244. Its totient is φ = 8265608064.

The previous prime is 20664020233. The next prime is 20664020263. The reversal of 20664020240 is 4202046602.

It can be written as a sum of positive squares in 2 ways, for example, as 12612188416 + 8051831824 = 112304^2 + 89732^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 129150047 + ... + 129150206.

Almost surely, 2^20664020240 is an apocalyptic number.

20664020240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20664020240 is an abundant number, since it is smaller than the sum of its proper divisors (27379827004).

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

20664020240 is a wasteful number, since it uses less digits than its factorization.

20664020240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 258300266 (or 258300260 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 26.

Adding to 20664020240 its reverse (4202046602), we get a palindrome (24866066842).

The spelling of 20664020240 in words is "twenty billion, six hundred sixty-four million, twenty thousand, two hundred forty".