126778997 has 2 divisors, whose sum is σ = 126778998. Its totient is φ = 126778996.

The previous prime is 126778991. The next prime is 126778999. The reversal of 126778997 is 799877621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 102434641 + 24344356 = 10121^2 + 4934^2 .

It is a cyclic number.

It is not a de Polignac number, because 126778997 - 2¹⁴ = 126762613 is a prime.

Together with 126778999, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (126778991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 63389498 + 63389499.

It is an arithmetic number, because the mean of its divisors is an integer number (63389499).

Almost surely, 2^126778997 is an apocalyptic number.

It is an amenable number.

126778997 is a deficient number, since it is larger than the sum of its proper divisors (1).

126778997 is an equidigital number, since it uses as much as digits as its factorization.

126778997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2667168, while the sum is 56.

The square root of 126778997 is about 11259.6179775337. The cubic root of 126778997 is about 502.3608314059.

The spelling of 126778997 in words is "one hundred twenty-six million, seven hundred seventy-eight thousand, nine hundred ninety-seven".