16421757121 has 72 divisors (see below), whose sum is σ = 22238195840. Its totient is φ = 11865553920.

The previous prime is 16421757091. The next prime is 16421757161. The reversal of 16421757121 is 12175712461.

It is not a de Polignac number, because 16421757121 - 2⁷ = 16421756993 is a prime.

It is a super-2 number, since 2×16421757121² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (16421757161) by changing a digit.

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 71 ways as a sum of consecutive naturals, for example, 17868700 + ... + 17869618.

Almost surely, 2^16421757121 is an apocalyptic number.

16421757121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16421757121 is a deficient number, since it is larger than the sum of its proper divisors (5816438719).

16421757121 is a wasteful number, since it uses less digits than its factorization.

16421757121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1055 (or 1027 counting only the distinct ones).

The product of its digits is 23520, while the sum is 37.

The spelling of 16421757121 in words is "sixteen billion, four hundred twenty-one million, seven hundred fifty-seven thousand, one hundred twenty-one".