40021320161 has 2 divisors, whose sum is σ = 40021320162. Its totient is φ = 40021320160.

The previous prime is 40021320121. The next prime is 40021320217. The reversal of 40021320161 is 16102312004.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23949419536 + 16071900625 = 154756^2 + 126775^2 .

It is a cyclic number.

It is not a de Polignac number, because 40021320161 - 2²² = 40017125857 is a prime.

It is a super-3 number, since 3×40021320161³ (a number of 33 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (40021320121) 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, 20010660080 + 20010660081.

It is an arithmetic number, because the mean of its divisors is an integer number (20010660081).

Almost surely, 2^40021320161 is an apocalyptic number.

It is an amenable number.

40021320161 is a deficient number, since it is larger than the sum of its proper divisors (1).

40021320161 is an equidigital number, since it uses as much as digits as its factorization.

40021320161 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 40021320161 its reverse (16102312004), we get a palindrome (56123632165).

The spelling of 40021320161 in words is "forty billion, twenty-one million, three hundred twenty thousand, one hundred sixty-one".