21071566156720 has 40 divisors (see below), whose sum is σ = 48992292569376. Its totient is φ = 8428471408128.

The previous prime is 21071566156691. The next prime is 21071566156721. The reversal of 21071566156720 is 2765166517012.

21071566156720 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-3 number, since 3×21071566156720³ (a number of 41 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21071566156721) 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, 2003404 + ... + 6793876.

Almost surely, 2^{21071566156720} is an apocalyptic number.

21071566156720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21071566156720 is an abundant number, since it is smaller than the sum of its proper divisors (27920726412656).

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

21071566156720 is a wasteful number, since it uses less digits than its factorization.

21071566156720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4845469 (or 4845463 counting only the distinct ones).

The product of its (nonzero) digits is 1058400, while the sum is 49.

The spelling of 21071566156720 in words is "twenty-one trillion, seventy-one billion, five hundred sixty-six million, one hundred fifty-six thousand, seven hundred twenty".