80401781 has 2 divisors, whose sum is σ = 80401782. Its totient is φ = 80401780.

The previous prime is 80401759. The next prime is 80401801. The reversal of 80401781 is 18710408.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 48580900 + 31820881 = 6970^2 + 5641^2 .

It is a cyclic number.

It is not a de Polignac number, because 80401781 - 2¹⁰ = 80400757 is a prime.

It is a super-2 number, since 2×80401781² = 12928892775943922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (80401081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40200890 + 40200891.

It is an arithmetic number, because the mean of its divisors is an integer number (40200891).

Almost surely, 2^80401781 is an apocalyptic number.

It is an amenable number.

80401781 is a deficient number, since it is larger than the sum of its proper divisors (1).

80401781 is an equidigital number, since it uses as much as digits as its factorization.

80401781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1792, while the sum is 29.

The square root of 80401781 is about 8966.7040209879. The cubic root of 80401781 is about 431.6070762110.

The spelling of 80401781 in words is "eighty million, four hundred one thousand, seven hundred eighty-one".