126665921 has 2 divisors, whose sum is σ = 126665922. Its totient is φ = 126665920.

The previous prime is 126665879. The next prime is 126665927. The reversal of 126665921 is 129566621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 94867600 + 31798321 = 9740^2 + 5639^2 .

It is a cyclic number.

It is not a de Polignac number, because 126665921 - 2⁶ = 126665857 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (126665927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 63332960 + 63332961.

It is an arithmetic number, because the mean of its divisors is an integer number (63332961).

Almost surely, 2^126665921 is an apocalyptic number.

It is an amenable number.

126665921 is a deficient number, since it is larger than the sum of its proper divisors (1).

126665921 is an equidigital number, since it uses as much as digits as its factorization.

126665921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 38880, while the sum is 38.

The square root of 126665921 is about 11254.5955502630. The cubic root of 126665921 is about 502.2114327109.

The spelling of 126665921 in words is "one hundred twenty-six million, six hundred sixty-five thousand, nine hundred twenty-one".