16616631532021 has 2 divisors, whose sum is σ = 16616631532022. Its totient is φ = 16616631532020.

The previous prime is 16616631532019. The next prime is 16616631532057. The reversal of 16616631532021 is 12023513661661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16392983880625 + 223647651396 = 4048825^2 + 472914^2 .

It is an emirp because it is prime and its reverse (12023513661661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16616631532021 - 2¹ = 16616631532019 is a prime.

It is a super-2 number, since 2×16616631532021² (a number of 27 digits) contains 22 as substring.

Together with 16616631532019, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16616631532321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8308315766010 + 8308315766011.

It is an arithmetic number, because the mean of its divisors is an integer number (8308315766011).

Almost surely, 2^{16616631532021} is an apocalyptic number.

It is an amenable number.

16616631532021 is a deficient number, since it is larger than the sum of its proper divisors (1).

16616631532021 is an equidigital number, since it uses as much as digits as its factorization.

16616631532021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 233280, while the sum is 43.

The spelling of 16616631532021 in words is "sixteen trillion, six hundred sixteen billion, six hundred thirty-one million, five hundred thirty-two thousand, twenty-one".