66904121 has 2 divisors, whose sum is σ = 66904122. Its totient is φ = 66904120.

The previous prime is 66904099. The next prime is 66904127. The reversal of 66904121 is 12140966.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42510400 + 24393721 = 6520^2 + 4939^2 .

It is a cyclic number.

It is not a de Polignac number, because 66904121 - 2¹⁰ = 66903097 is a prime.

It is a super-2 number, since 2×66904121² = 8952322813565282, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66904127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33452060 + 33452061.

It is an arithmetic number, because the mean of its divisors is an integer number (33452061).

Almost surely, 2^66904121 is an apocalyptic number.

It is an amenable number.

66904121 is a deficient number, since it is larger than the sum of its proper divisors (1).

66904121 is an equidigital number, since it uses as much as digits as its factorization.

66904121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 66904121 is about 8179.4939330010. The cubic root of 66904121 is about 405.9609776694.

The spelling of 66904121 in words is "sixty-six million, nine hundred four thousand, one hundred twenty-one".