977986781 has 2 divisors, whose sum is σ = 977986782. Its totient is φ = 977986780.

The previous prime is 977986769. The next prime is 977986813. The reversal of 977986781 is 187689779.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 633327556 + 344659225 = 25166^2 + 18565^2 .

It is a cyclic number.

It is not a de Polignac number, because 977986781 - 2⁶ = 977986717 is a prime.

It is a super-2 number, since 2×977986781² = 1912916287621483922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (977986721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 488993390 + 488993391.

It is an arithmetic number, because the mean of its divisors is an integer number (488993391).

Almost surely, 2^977986781 is an apocalyptic number.

It is an amenable number.

977986781 is a deficient number, since it is larger than the sum of its proper divisors (1).

977986781 is an equidigital number, since it uses as much as digits as its factorization.

977986781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10668672, while the sum is 62.

The square root of 977986781 is about 31272.7801930049. The cubic root of 977986781 is about 992.6077496184.

The spelling of 977986781 in words is "nine hundred seventy-seven million, nine hundred eighty-six thousand, seven hundred eighty-one".