21171012215212 has 24 divisors (see below), whose sum is σ = 38061921788352. Its totient is φ = 10298138970000.

The previous prime is 21171012215209. The next prime is 21171012215237. The reversal of 21171012215212 is 21251221017112.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 245150614 + ... + 245236957.

It is an arithmetic number, because the mean of its divisors is an integer number (1585913407848).

Almost surely, 2^{21171012215212} is an apocalyptic number.

It is an amenable number.

21171012215212 is a deficient number, since it is larger than the sum of its proper divisors (16890909573140).

21171012215212 is a wasteful number, since it uses less digits than its factorization.

21171012215212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 490387869 (or 490387867 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 28.

The spelling of 21171012215212 in words is "twenty-one trillion, one hundred seventy-one billion, twelve million, two hundred fifteen thousand, two hundred twelve".