6981539777 has 2 divisors, whose sum is σ = 6981539778. Its totient is φ = 6981539776.

The previous prime is 6981539713. The next prime is 6981539801. The reversal of 6981539777 is 7779351896.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4489134001 + 2492405776 = 67001^2 + 49924^2 .

It is a cyclic number.

It is not a de Polignac number, because 6981539777 - 2⁶ = 6981539713 is a prime.

It is not a weakly prime, because it can be changed into another prime (6981559777) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3490769888 + 3490769889.

It is an arithmetic number, because the mean of its divisors is an integer number (3490769889).

Almost surely, 2^6981539777 is an apocalyptic number.

It is an amenable number.

6981539777 is a deficient number, since it is larger than the sum of its proper divisors (1).

6981539777 is an equidigital number, since it uses as much as digits as its factorization.

6981539777 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20003760, while the sum is 62.

The square root of 6981539777 is about 83555.6088901278. The cubic root of 6981539777 is about 1911.2481244828.

The spelling of 6981539777 in words is "six billion, nine hundred eighty-one million, five hundred thirty-nine thousand, seven hundred seventy-seven".