1616866210021 has 2 divisors, whose sum is σ = 1616866210022. Its totient is φ = 1616866210020.

The previous prime is 1616866210007. The next prime is 1616866210097. The reversal of 1616866210021 is 1200126686161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1442569144900 + 174297065121 = 1201070^2 + 417489^2 .

It is a cyclic number.

It is not a de Polignac number, because 1616866210021 - 2⁹ = 1616866209509 is a prime.

It is a super-2 number, since 2×1616866210021² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1616866210121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 808433105010 + 808433105011.

It is an arithmetic number, because the mean of its divisors is an integer number (808433105011).

Almost surely, 2^{1616866210021} is an apocalyptic number.

It is an amenable number.

1616866210021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1616866210021 is an equidigital number, since it uses as much as digits as its factorization.

1616866210021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 41472, while the sum is 40.

The spelling of 1616866210021 in words is "one trillion, six hundred sixteen billion, eight hundred sixty-six million, two hundred ten thousand, twenty-one".