21948987066 has 16 divisors (see below), whose sum is σ = 44120808864. Its totient is φ = 7279189904.

The previous prime is 21948987061. The next prime is 21948987089. The reversal of 21948987066 is 66078984912.

It is not an unprimeable number, because it can be changed into a prime (21948987061) 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, 9283500 + ... + 9285863.

It is an arithmetic number, because the mean of its divisors is an integer number (2757550554).

Almost surely, 2^21948987066 is an apocalyptic number.

21948987066 is an abundant number, since it is smaller than the sum of its proper divisors (22171821798).

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

21948987066 is a wasteful number, since it uses less digits than its factorization.

21948987066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18569565.

The product of its (nonzero) digits is 10450944, while the sum is 60.

The spelling of 21948987066 in words is "twenty-one billion, nine hundred forty-eight million, nine hundred eighty-seven thousand, sixty-six".