21506666321312 has 48 divisors (see below), whose sum is σ = 42571876838400. Its totient is φ = 10694784764160.

The previous prime is 21506666321303. The next prime is 21506666321323. The reversal of 21506666321312 is 21312366660512.

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, 28902989 + ... + 29637747.

It is an arithmetic number, because the mean of its divisors is an integer number (886914100800).

Almost surely, 2^{21506666321312} is an apocalyptic number.

It is an amenable number.

21506666321312 is a deficient number, since it is larger than the sum of its proper divisors (21065210517088).

21506666321312 is a wasteful number, since it uses less digits than its factorization.

21506666321312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 739749 (or 739741 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 44.

The spelling of 21506666321312 in words is "twenty-one trillion, five hundred six billion, six hundred sixty-six million, three hundred twenty-one thousand, three hundred twelve".