20908019521 has 8 divisors (see below), whose sum is σ = 22041984384. Its totient is φ = 19792798080.

The previous prime is 20908019519. The next prime is 20908019557. The reversal of 20908019521 is 12591080902.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20908019521 - 2¹ = 20908019519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20908019581) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4683565 + ... + 4688026.

It is an arithmetic number, because the mean of its divisors is an integer number (2755248048).

Almost surely, 2^20908019521 is an apocalyptic number.

It is an amenable number.

20908019521 is a deficient number, since it is larger than the sum of its proper divisors (1133964863).

20908019521 is an equidigital number, since it uses as much as digits as its factorization.

20908019521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9371711.

The product of its (nonzero) digits is 12960, while the sum is 37.

The spelling of 20908019521 in words is "twenty billion, nine hundred eight million, nineteen thousand, five hundred twenty-one".