21221546646042 has 12 divisors (see below), whose sum is σ = 45980017733130. Its totient is φ = 7073848882008.

The previous prime is 21221546646029. The next prime is 21221546646067. The reversal of 21221546646042 is 24064664512212.

21221546646042 is a `hidden beast` number, since 2 + 1 + 2 + 2 + 1 + 546 + 6 + 4 + 60 + 42 = 666.

It can be written as a sum of positive squares in only one way, i.e., 19015189930881 + 2206356715161 = 4360641^2 + 1485381^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 589487406817 + ... + 589487406852.

Almost surely, 2^{21221546646042} is an apocalyptic number.

21221546646042 is an abundant number, since it is smaller than the sum of its proper divisors (24758471087088).

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

21221546646042 is a wasteful number, since it uses less digits than its factorization.

21221546646042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1178974813677 (or 1178974813674 counting only the distinct ones).

The product of its (nonzero) digits is 1105920, while the sum is 45.

The spelling of 21221546646042 in words is "twenty-one trillion, two hundred twenty-one billion, five hundred forty-six million, six hundred forty-six thousand, forty-two".