21663411150066 has 96 divisors (see below), whose sum is σ = 53922978083520. Its totient is φ = 5767652822400.

The previous prime is 21663411149957. The next prime is 21663411150067. The reversal of 21663411150066 is 66005111436612.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (21663411150067) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 31447465 + ... + 32128956.

It is an arithmetic number, because the mean of its divisors is an integer number (561697688370).

Almost surely, 2^{21663411150066} is an apocalyptic number.

21663411150066 is an abundant number, since it is smaller than the sum of its proper divisors (32259566933454).

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

21663411150066 is a wasteful number, since it uses less digits than its factorization.

21663411150066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63576520 (or 63576513 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 42.

Adding to 21663411150066 its reverse (66005111436612), we get a palindrome (87668522586678).

The spelling of 21663411150066 in words is "twenty-one trillion, six hundred sixty-three billion, four hundred eleven million, one hundred fifty thousand, sixty-six".