21946991066 has 64 divisors (see below), whose sum is σ = 44228007936. Its totient is φ = 7888190400.

The previous prime is 21946991009. The next prime is 21946991089. The reversal of 21946991066 is 66019964912.

It is a junction number, because it is equal to n+sod(n) for n = 21946990999 and 21946991017.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5609651 + ... + 5613561.

It is an arithmetic number, because the mean of its divisors is an integer number (691062624).

Almost surely, 2^21946991066 is an apocalyptic number.

21946991066 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21946991066 is an abundant number, since it is smaller than the sum of its proper divisors (22281016870).

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

21946991066 is a wasteful number, since it uses less digits than its factorization.

21946991066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6747.

The product of its (nonzero) digits is 1259712, while the sum is 53.

The spelling of 21946991066 in words is "twenty-one billion, nine hundred forty-six million, nine hundred ninety-one thousand, sixty-six".