97778491 has 2 divisors, whose sum is σ = 97778492. Its totient is φ = 97778490.

The previous prime is 97778489. The next prime is 97778521. The reversal of 97778491 is 19487779.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 97778491 - 2¹ = 97778489 is a prime.

Together with 97778489, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (97778411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48889245 + 48889246.

It is an arithmetic number, because the mean of its divisors is an integer number (48889246).

Almost surely, 2^97778491 is an apocalyptic number.

97778491 is a deficient number, since it is larger than the sum of its proper divisors (1).

97778491 is an equidigital number, since it uses as much as digits as its factorization.

97778491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 889056, while the sum is 52.

The square root of 97778491 is about 9888.3007134694. The cubic root of 97778491 is about 460.6960021497.

The spelling of 97778491 in words is "ninety-seven million, seven hundred seventy-eight thousand, four hundred ninety-one".