665551477 has 2 divisors, whose sum is σ = 665551478. Its totient is φ = 665551476.

The previous prime is 665551459. The next prime is 665551489. The reversal of 665551477 is 774155566.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 347785201 + 317766276 = 18649^2 + 17826^2 .

It is a cyclic number.

It is not a de Polignac number, because 665551477 - 2¹¹ = 665549429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665551427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332775738 + 332775739.

It is an arithmetic number, because the mean of its divisors is an integer number (332775739).

Almost surely, 2^665551477 is an apocalyptic number.

It is an amenable number.

665551477 is a deficient number, since it is larger than the sum of its proper divisors (1).

665551477 is an equidigital number, since it uses as much as digits as its factorization.

665551477 is an evil number, because the sum of its binary digits is even.

The product of its digits is 882000, while the sum is 46.

The square root of 665551477 is about 25798.2843809429. The cubic root of 665551477 is about 873.0930889233.

The spelling of 665551477 in words is "six hundred sixty-five million, five hundred fifty-one thousand, four hundred seventy-seven".