84717717781 has 2 divisors, whose sum is σ = 84717717782. Its totient is φ = 84717717780.

The previous prime is 84717717743. The next prime is 84717717797. The reversal of 84717717781 is 18771771748.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 81415491556 + 3302226225 = 285334^2 + 57465^2 .

It is a cyclic number.

It is not a de Polignac number, because 84717717781 - 2⁷ = 84717717653 is a prime.

It is a super-2 number, since 2×84717717781² (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 (84717717481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42358858890 + 42358858891.

It is an arithmetic number, because the mean of its divisors is an integer number (42358858891).

Almost surely, 2^84717717781 is an apocalyptic number.

It is an amenable number.

84717717781 is a deficient number, since it is larger than the sum of its proper divisors (1).

84717717781 is an equidigital number, since it uses as much as digits as its factorization.

84717717781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4302592, while the sum is 58.

The spelling of 84717717781 in words is "eighty-four billion, seven hundred seventeen million, seven hundred seventeen thousand, seven hundred eighty-one".