21671216666970 has 128 divisors (see below), whose sum is σ = 57438529747200. Its totient is φ = 5198845470720.

The previous prime is 21671216666959. The next prime is 21671216667013. The reversal of 21671216666970 is 7966661217612.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 14426956 + ... + 15858104.

It is an arithmetic number, because the mean of its divisors is an integer number (448738513650).

Almost surely, 2^{21671216666970} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21671216666970, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28719264873600).

21671216666970 is an abundant number, since it is smaller than the sum of its proper divisors (35767313080230).

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

21671216666970 is a wasteful number, since it uses less digits than its factorization.

21671216666970 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1432160.

The product of its (nonzero) digits is 13716864, while the sum is 60.

The spelling of 21671216666970 in words is "twenty-one trillion, six hundred seventy-one billion, two hundred sixteen million, six hundred sixty-six thousand, nine hundred seventy".