161453210021 has 2 divisors, whose sum is σ = 161453210022. Its totient is φ = 161453210020.

The previous prime is 161453210003. The next prime is 161453210047. The reversal of 161453210021 is 120012354161.

It is an a-pointer prime, because the next prime (161453210047) can be obtained adding 161453210021 to its sum of digits (26).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 159132379396 + 2320830625 = 398914^2 + 48175^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161453210021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161453210081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80726605010 + 80726605011.

It is an arithmetic number, because the mean of its divisors is an integer number (80726605011).

Almost surely, 2^161453210021 is an apocalyptic number.

It is an amenable number.

161453210021 is a deficient number, since it is larger than the sum of its proper divisors (1).

161453210021 is an equidigital number, since it uses as much as digits as its factorization.

161453210021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1440, while the sum is 26.

Adding to 161453210021 its reverse (120012354161), we get a palindrome (281465564182).

The spelling of 161453210021 in words is "one hundred sixty-one billion, four hundred fifty-three million, two hundred ten thousand, twenty-one".