126698021 has 2 divisors, whose sum is σ = 126698022. Its totient is φ = 126698020.

The previous prime is 126698017. The next prime is 126698051. The reversal of 126698021 is 120896621.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 93508900 + 33189121 = 9670^2 + 5761^2 .

It is a cyclic number.

It is not a de Polignac number, because 126698021 - 2² = 126698017 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (126698051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 63349010 + 63349011.

It is an arithmetic number, because the mean of its divisors is an integer number (63349011).

Almost surely, 2^126698021 is an apocalyptic number.

It is an amenable number.

126698021 is a deficient number, since it is larger than the sum of its proper divisors (1).

126698021 is an equidigital number, since it uses as much as digits as its factorization.

126698021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 126698021 is about 11256.0215440448. The cubic root of 126698021 is about 502.2538530274.

The spelling of 126698021 in words is "one hundred twenty-six million, six hundred ninety-eight thousand, twenty-one".