9781238977 has 2 divisors, whose sum is σ = 9781238978. Its totient is φ = 9781238976.

The previous prime is 9781238953. The next prime is 9781239019. The reversal of 9781238977 is 7798321879.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7409938561 + 2371300416 = 86081^2 + 48696^2 .

It is a cyclic number.

It is not a de Polignac number, because 9781238977 - 2³¹ = 7633755329 is a prime.

It is not a weakly prime, because it can be changed into another prime (9781233977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4890619488 + 4890619489.

It is an arithmetic number, because the mean of its divisors is an integer number (4890619489).

Almost surely, 2^9781238977 is an apocalyptic number.

It is an amenable number.

9781238977 is a deficient number, since it is larger than the sum of its proper divisors (1).

9781238977 is an equidigital number, since it uses as much as digits as its factorization.

9781238977 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10668672, while the sum is 61.

The square root of 9781238977 is about 98900.1464963526. The cubic root of 9781238977 is about 2138.6085064884.

The spelling of 9781238977 in words is "nine billion, seven hundred eighty-one million, two hundred thirty-eight thousand, nine hundred seventy-seven".