20671215621 has 8 divisors (see below), whose sum is σ = 31498995264. Its totient is φ = 11812123200.

The previous prime is 20671215583. The next prime is 20671215641. The reversal of 20671215621 is 12651217602.

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

It is not a de Polignac number, because 20671215621 - 2¹³ = 20671207429 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20671215641) 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, 492171780 + ... + 492171821.

It is an arithmetic number, because the mean of its divisors is an integer number (3937374408).

Almost surely, 2^20671215621 is an apocalyptic number.

20671215621 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20671215621 is a deficient number, since it is larger than the sum of its proper divisors (10827779643).

20671215621 is an equidigital number, since it uses as much as digits as its factorization.

20671215621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 984343611.

The product of its (nonzero) digits is 10080, while the sum is 33.

The spelling of 20671215621 in words is "twenty billion, six hundred seventy-one million, two hundred fifteen thousand, six hundred twenty-one".