40521920161 has 2 divisors, whose sum is σ = 40521920162. Its totient is φ = 40521920160.

The previous prime is 40521920107. The next prime is 40521920177. The reversal of 40521920161 is 16102912504.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27078677136 + 13443243025 = 164556^2 + 115945^2 .

It is a cyclic number.

It is not a de Polignac number, because 40521920161 - 2⁹ = 40521919649 is a prime.

It is not a weakly prime, because it can be changed into another prime (40521920261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20260960080 + 20260960081.

It is an arithmetic number, because the mean of its divisors is an integer number (20260960081).

Almost surely, 2^40521920161 is an apocalyptic number.

It is an amenable number.

40521920161 is a deficient number, since it is larger than the sum of its proper divisors (1).

40521920161 is an equidigital number, since it uses as much as digits as its factorization.

40521920161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4320, while the sum is 31.

The spelling of 40521920161 in words is "forty billion, five hundred twenty-one million, nine hundred twenty thousand, one hundred sixty-one".