16161120021 has 8 divisors (see below), whose sum is σ = 21548753920. Its totient is φ = 10773783072.

The previous prime is 16161120007. The next prime is 16161120061. The reversal of 16161120021 is 12002116161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 16161120021 - 2¹⁵ = 16161087253 is a prime.

It is a super-2 number, since 2×16161120021² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 16161120021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16161120061) 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, 146625 + ... + 231993.

It is an arithmetic number, because the mean of its divisors is an integer number (2693594240).

Almost surely, 2^16161120021 is an apocalyptic number.

It is an amenable number.

16161120021 is a deficient number, since it is larger than the sum of its proper divisors (5387633899).

16161120021 is an equidigital number, since it uses as much as digits as its factorization.

16161120021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148475.

The product of its (nonzero) digits is 144, while the sum is 21.

Adding to 16161120021 its reverse (12002116161), we get a palindrome (28163236182).

The spelling of 16161120021 in words is "sixteen billion, one hundred sixty-one million, one hundred twenty thousand, twenty-one".