16671163021 has 4 divisors (see below), whose sum is σ = 16755788412. Its totient is φ = 16586537632.

The previous prime is 16671163009. The next prime is 16671163051. The reversal of 16671163021 is 12036117661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12036117661 = 67531 ⋅178231.

It can be written as a sum of positive squares in 2 ways, for example, as 15603507396 + 1067655625 = 124914^2 + 32675^2 .

It is a cyclic number.

It is not a de Polignac number, because 16671163021 - 2²¹ = 16669065869 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16671163051) 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, 42312400 + ... + 42312793.

It is an arithmetic number, because the mean of its divisors is an integer number (4188947103).

Almost surely, 2^16671163021 is an apocalyptic number.

It is an amenable number.

16671163021 is a deficient number, since it is larger than the sum of its proper divisors (84625391).

16671163021 is an equidigital number, since it uses as much as digits as its factorization.

16671163021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84625390.

The product of its (nonzero) digits is 9072, while the sum is 34.

The spelling of 16671163021 in words is "sixteen billion, six hundred seventy-one million, one hundred sixty-three thousand, twenty-one".