87731703781 has 2 divisors, whose sum is σ = 87731703782. Its totient is φ = 87731703780.

The previous prime is 87731703749. The next prime is 87731703799. The reversal of 87731703781 is 18730713778.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 84663540900 + 3068162881 = 290970^2 + 55391^2 .

It is a cyclic number.

It is not a de Polignac number, because 87731703781 - 2⁵ = 87731703749 is a prime.

It is a super-2 number, since 2×87731703781² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87731706781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43865851890 + 43865851891.

It is an arithmetic number, because the mean of its divisors is an integer number (43865851891).

Almost surely, 2^87731703781 is an apocalyptic number.

It is an amenable number.

87731703781 is a deficient number, since it is larger than the sum of its proper divisors (1).

87731703781 is an equidigital number, since it uses as much as digits as its factorization.

87731703781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1382976, while the sum is 52.

The spelling of 87731703781 in words is "eighty-seven billion, seven hundred thirty-one million, seven hundred three thousand, seven hundred eighty-one".