66763421 has 2 divisors, whose sum is σ = 66763422. Its totient is φ = 66763420.

The previous prime is 66763409. The next prime is 66763441. The reversal of 66763421 is 12436766.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 40896025 + 25867396 = 6395^2 + 5086^2 .

It is a cyclic number.

It is not a de Polignac number, because 66763421 - 2⁶ = 66763357 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66763441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33381710 + 33381711.

It is an arithmetic number, because the mean of its divisors is an integer number (33381711).

Almost surely, 2^66763421 is an apocalyptic number.

It is an amenable number.

66763421 is a deficient number, since it is larger than the sum of its proper divisors (1).

66763421 is an equidigital number, since it uses as much as digits as its factorization.

66763421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36288, while the sum is 35.

The square root of 66763421 is about 8170.8886297636. Note that the first 3 decimals coincide. The cubic root of 66763421 is about 405.6761980179.

The spelling of 66763421 in words is "sixty-six million, seven hundred sixty-three thousand, four hundred twenty-one".