81630161401 has 2 divisors, whose sum is σ = 81630161402. Its totient is φ = 81630161400.

The previous prime is 81630161357. The next prime is 81630161447. The reversal of 81630161401 is 10416103618.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 70690047376 + 10940114025 = 265876^2 + 104595^2 .

It is a cyclic number.

It is not a de Polignac number, because 81630161401 - 2¹⁵ = 81630128633 is a prime.

It is not a weakly prime, because it can be changed into another prime (81630161801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40815080700 + 40815080701.

It is an arithmetic number, because the mean of its divisors is an integer number (40815080701).

Almost surely, 2^81630161401 is an apocalyptic number.

It is an amenable number.

81630161401 is a deficient number, since it is larger than the sum of its proper divisors (1).

81630161401 is an equidigital number, since it uses as much as digits as its factorization.

81630161401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 31.

The spelling of 81630161401 in words is "eighty-one billion, six hundred thirty million, one hundred sixty-one thousand, four hundred one".