97782781 has 2 divisors, whose sum is σ = 97782782. Its totient is φ = 97782780.

The previous prime is 97782767. The next prime is 97782851. The reversal of 97782781 is 18728779.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 83083225 + 14699556 = 9115^2 + 3834^2 .

It is a cyclic number.

It is not a de Polignac number, because 97782781 - 2²⁵ = 64228349 is a prime.

It is a super-2 number, since 2×97782781² = 19122944520187922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (97782281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48891390 + 48891391.

It is an arithmetic number, because the mean of its divisors is an integer number (48891391).

Almost surely, 2^97782781 is an apocalyptic number.

It is an amenable number.

97782781 is a deficient number, since it is larger than the sum of its proper divisors (1).

97782781 is an equidigital number, since it uses as much as digits as its factorization.

97782781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 395136, while the sum is 49.

The square root of 97782781 is about 9888.5176341047. The cubic root of 97782781 is about 460.7027396811.

The spelling of 97782781 in words is "ninety-seven million, seven hundred eighty-two thousand, seven hundred eighty-one".