21530166435 has 24 divisors (see below), whose sum is σ = 38186841264. Its totient is φ = 11215713600.

The previous prime is 21530166403. The next prime is 21530166473. The reversal of 21530166435 is 53466103512.

21530166435 is a `hidden beast` number, since 2 + 1 + 5 + 3 + 0 + 1 + 6 + 643 + 5 = 666.

It is not a de Polignac number, because 21530166435 - 2⁵ = 21530166403 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21530166435.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5561416 + ... + 5565285.

It is an arithmetic number, because the mean of its divisors is an integer number (1591118386).

Almost surely, 2^21530166435 is an apocalyptic number.

21530166435 is a deficient number, since it is larger than the sum of its proper divisors (16656674829).

21530166435 is a wasteful number, since it uses less digits than its factorization.

21530166435 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11126755 (or 11126752 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 36.

Adding to 21530166435 its reverse (53466103512), we get a palindrome (74996269947).

The spelling of 21530166435 in words is "twenty-one billion, five hundred thirty million, one hundred sixty-six thousand, four hundred thirty-five".