20317251621 has 8 divisors (see below), whose sum is σ = 27241008480. Its totient is φ = 13469164592.

The previous prime is 20317251571. The next prime is 20317251637. The reversal of 20317251621 is 12615271302.

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 20317251621 - 2¹¹ = 20317249573 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20317251121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18916830 + ... + 18917903.

It is an arithmetic number, because the mean of its divisors is an integer number (3405126060).

Almost surely, 2^20317251621 is an apocalyptic number.

It is an amenable number.

20317251621 is a deficient number, since it is larger than the sum of its proper divisors (6923756859).

20317251621 is a wasteful number, since it uses less digits than its factorization.

20317251621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37834915.

The product of its (nonzero) digits is 5040, while the sum is 30.

The spelling of 20317251621 in words is "twenty billion, three hundred seventeen million, two hundred fifty-one thousand, six hundred twenty-one".