20021009508 has 18 divisors (see below), whose sum is σ = 50608663014. Its totient is φ = 6673669824.

The previous prime is 20021009483. The next prime is 20021009509. The reversal of 20021009508 is 80590012002.

It can be written as a sum of positive squares in only one way, i.e., 12485380644 + 7535628864 = 111738^2 + 86808^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is not an unprimeable number, because it can be changed into a prime (20021009509) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 278069541 + ... + 278069612.

Almost surely, 2^20021009508 is an apocalyptic number.

It is an amenable number.

20021009508 is an abundant number, since it is smaller than the sum of its proper divisors (30587653506).

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

20021009508 is a wasteful number, since it uses less digits than its factorization.

20021009508 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 556139163 (or 556139158 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The spelling of 20021009508 in words is "twenty billion, twenty-one million, nine thousand, five hundred eight".