87856781393 has 2 divisors, whose sum is σ = 87856781394. Its totient is φ = 87856781392.

The previous prime is 87856781329. The next prime is 87856781461. The reversal of 87856781393 is 39318765878.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 87729700864 + 127080529 = 296192^2 + 11273^2 .

It is a cyclic number.

It is not a de Polignac number, because 87856781393 - 2⁶ = 87856781329 is a prime.

It is not a weakly prime, because it can be changed into another prime (87856781693) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43928390696 + 43928390697.

It is an arithmetic number, because the mean of its divisors is an integer number (43928390697).

Almost surely, 2^87856781393 is an apocalyptic number.

It is an amenable number.

87856781393 is a deficient number, since it is larger than the sum of its proper divisors (1).

87856781393 is an equidigital number, since it uses as much as digits as its factorization.

87856781393 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 60963840, while the sum is 65.

The spelling of 87856781393 in words is "eighty-seven billion, eight hundred fifty-six million, seven hundred eighty-one thousand, three hundred ninety-three".