66820763 has 2 divisors, whose sum is σ = 66820764. Its totient is φ = 66820762.

The previous prime is 66820759. The next prime is 66820811. The reversal of 66820763 is 36702866.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66820763 - 2² = 66820759 is a prime.

It is not a weakly prime, because it can be changed into another prime (66820363) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33410381 + 33410382.

It is an arithmetic number, because the mean of its divisors is an integer number (33410382).

Almost surely, 2^66820763 is an apocalyptic number.

66820763 is a deficient number, since it is larger than the sum of its proper divisors (1).

66820763 is an equidigital number, since it uses as much as digits as its factorization.

66820763 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72576, while the sum is 38.

The square root of 66820763 is about 8174.3967973178. The cubic root of 66820763 is about 405.7923076455.

The spelling of 66820763 in words is "sixty-six million, eight hundred twenty thousand, seven hundred sixty-three".