661477 has 2 divisors, whose sum is σ = 661478. Its totient is φ = 661476.

The previous prime is 661459. The next prime is 661481. The reversal of 661477 is 774166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 617796 + 43681 = 786^2 + 209^2 .

It is a cyclic number.

It is not a de Polignac number, because 661477 - 2¹⁵ = 628709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661417) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330738 + 330739.

It is an arithmetic number, because the mean of its divisors is an integer number (330739).

2⁶⁶¹⁴⁷⁷ is an apocalyptic number.

It is an amenable number.

661477 is a deficient number, since it is larger than the sum of its proper divisors (1).

661477 is an equidigital number, since it uses as much as digits as its factorization.

661477 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7056, while the sum is 31.

The square root of 661477 is about 813.3123631176. The cubic root of 661477 is about 87.1307761499.

The spelling of 661477 in words is "six hundred sixty-one thousand, four hundred seventy-seven".