21211166652 has 96 divisors (see below), whose sum is σ = 53611488000. Its totient is φ = 6488501760.

The previous prime is 21211166621. The next prime is 21211166719. The reversal of 21211166652 is 25666111212.

It is a congruent number.

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, 40556463 + ... + 40556985.

It is an arithmetic number, because the mean of its divisors is an integer number (558453000).

Almost surely, 2^21211166652 is an apocalyptic number.

It is an amenable number.

21211166652 is an abundant number, since it is smaller than the sum of its proper divisors (32400321348).

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

21211166652 is a wasteful number, since it uses less digits than its factorization.

21211166652 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1563 (or 1561 counting only the distinct ones).

The product of its digits is 8640, while the sum is 33.

Adding to 21211166652 its reverse (25666111212), we get a palindrome (46877277864).

The spelling of 21211166652 in words is "twenty-one billion, two hundred eleven million, one hundred sixty-six thousand, six hundred fifty-two".