16161020605021 has 4 divisors (see below), whose sum is σ = 16162919006652. Its totient is φ = 16159122203392.

The previous prime is 16161020605007. The next prime is 16161020605031. The reversal of 16161020605021 is 12050602016161.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15648242877796 + 512777727225 = 3955786^2 + 716085^2 .

It is a cyclic number.

It is not a de Polignac number, because 16161020605021 - 2²⁵ = 16160987050589 is a prime.

It is a super-2 number, since 2×16161020605021² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16161020605031) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 949188046 + ... + 949205071.

It is an arithmetic number, because the mean of its divisors is an integer number (4040729751663).

Almost surely, 2^{16161020605021} is an apocalyptic number.

It is an amenable number.

16161020605021 is a deficient number, since it is larger than the sum of its proper divisors (1898401631).

16161020605021 is an equidigital number, since it uses as much as digits as its factorization.

16161020605021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1898401630.

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

The spelling of 16161020605021 in words is "sixteen trillion, one hundred sixty-one billion, twenty million, six hundred five thousand, twenty-one".