16773331621 has 2 divisors, whose sum is σ = 16773331622. Its totient is φ = 16773331620.

The previous prime is 16773331573. The next prime is 16773331657. The reversal of 16773331621 is 12613337761.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15354679396 + 1418652225 = 123914^2 + 37665^2 .

It is an emirp because it is prime and its reverse (12613337761) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16773331621 - 2¹³ = 16773323429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16773331661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8386665810 + 8386665811.

It is an arithmetic number, because the mean of its divisors is an integer number (8386665811).

Almost surely, 2^16773331621 is an apocalyptic number.

It is an amenable number.

16773331621 is a deficient number, since it is larger than the sum of its proper divisors (1).

16773331621 is an equidigital number, since it uses as much as digits as its factorization.

16773331621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 95256, while the sum is 40.

The spelling of 16773331621 in words is "sixteen billion, seven hundred seventy-three million, three hundred thirty-one thousand, six hundred twenty-one".