40205420051081 has 2 divisors, whose sum is σ = 40205420051082. Its totient is φ = 40205420051080.

The previous prime is 40205420051077. The next prime is 40205420051107. The reversal of 40205420051081 is 18015002450204.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28210799995456 + 11994620055625 = 5311384^2 + 3463325^2 .

It is a cyclic number.

It is not a de Polignac number, because 40205420051081 - 2² = 40205420051077 is a prime.

It is a super-2 number, since 2×40205420051081² (a number of 28 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (40205420051681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20102710025540 + 20102710025541.

It is an arithmetic number, because the mean of its divisors is an integer number (20102710025541).

Almost surely, 2^{40205420051081} is an apocalyptic number.

It is an amenable number.

40205420051081 is a deficient number, since it is larger than the sum of its proper divisors (1).

40205420051081 is an equidigital number, since it uses as much as digits as its factorization.

40205420051081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12800, while the sum is 32.

The spelling of 40205420051081 in words is "forty trillion, two hundred five billion, four hundred twenty million, fifty-one thousand, eighty-one".