801864781 has 2 divisors, whose sum is σ = 801864782. Its totient is φ = 801864780.

The previous prime is 801864671. The next prime is 801864821. The reversal of 801864781 is 187468108.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 536663556 + 265201225 = 23166^2 + 16285^2 .

It is a cyclic number.

It is not a de Polignac number, because 801864781 - 2¹³ = 801856589 is a prime.

It is a super-2 number, since 2×801864781² = 1285974254016355922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (801864281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 400932390 + 400932391.

It is an arithmetic number, because the mean of its divisors is an integer number (400932391).

Almost surely, 2^801864781 is an apocalyptic number.

It is an amenable number.

801864781 is a deficient number, since it is larger than the sum of its proper divisors (1).

801864781 is an equidigital number, since it uses as much as digits as its factorization.

801864781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 86016, while the sum is 43.

The square root of 801864781 is about 28317.2170419340. The cubic root of 801864781 is about 929.0385025618.

The spelling of 801864781 in words is "eight hundred one million, eight hundred sixty-four thousand, seven hundred eighty-one".