2066161021621 has 8 divisors (see below), whose sum is σ = 2068456915224. Its totient is φ = 2063865323520.

The previous prime is 2066161021583. The next prime is 2066161021637. The reversal of 2066161021621 is 1261201616602.

It can be written as a sum of positive squares in 4 ways, for example, as 251563436721 + 1814597584900 = 501561^2 + 1347070^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 2066161021621 - 2¹³ = 2066161013429 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 (2066161021681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34313781 + ... + 34373941.

It is an arithmetic number, because the mean of its divisors is an integer number (258557114403).

Almost surely, 2^{2066161021621} is an apocalyptic number.

It is an amenable number.

2066161021621 is a deficient number, since it is larger than the sum of its proper divisors (2295893603).

2066161021621 is an equidigital number, since it uses as much as digits as its factorization.

2066161021621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97751.

The product of its (nonzero) digits is 10368, while the sum is 34.

The spelling of 2066161021621 in words is "two trillion, sixty-six billion, one hundred sixty-one million, twenty-one thousand, six hundred twenty-one".