863221267561 has 2 divisors, whose sum is σ = 863221267562. Its totient is φ = 863221267560.

The previous prime is 863221267553. The next prime is 863221267577. The reversal of 863221267561 is 165762122368.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 539665075161 + 323556192400 = 734619^2 + 568820^2 .

It is a cyclic number.

It is not a de Polignac number, because 863221267561 - 2³ = 863221267553 is a prime.

It is not a weakly prime, because it can be changed into another prime (863221267061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 431610633780 + 431610633781.

It is an arithmetic number, because the mean of its divisors is an integer number (431610633781).

Almost surely, 2^863221267561 is an apocalyptic number.

It is an amenable number.

863221267561 is a deficient number, since it is larger than the sum of its proper divisors (1).

863221267561 is an equidigital number, since it uses as much as digits as its factorization.

863221267561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1451520, while the sum is 49.

The spelling of 863221267561 in words is "eight hundred sixty-three billion, two hundred twenty-one million, two hundred sixty-seven thousand, five hundred sixty-one".