16166121520 has 40 divisors (see below), whose sum is σ = 37603191456. Its totient is φ = 6463531008.

The previous prime is 16166121479. The next prime is 16166121523. The reversal of 16166121520 is 2512166161.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×16166121520² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (16166121523) 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, 137389 + ... + 226291.

Almost surely, 2^16166121520 is an apocalyptic number.

16166121520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

16166121520 is an abundant number, since it is smaller than the sum of its proper divisors (21437069936).

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

16166121520 is a wasteful number, since it uses less digits than its factorization.

16166121520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91189 (or 91183 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 31.

Adding to 16166121520 its reverse (2512166161), we get a palindrome (18678287681).

The spelling of 16166121520 in words is "sixteen billion, one hundred sixty-six million, one hundred twenty-one thousand, five hundred twenty".