661465471 has 2 divisors, whose sum is σ = 661465472. Its totient is φ = 661465470.

The previous prime is 661465459. The next prime is 661465477. The reversal of 661465471 is 174564166.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 661465471 - 2⁹ = 661464959 is a prime.

It is a super-3 number, since 3×661465471³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661465477) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330732735 + 330732736.

It is an arithmetic number, because the mean of its divisors is an integer number (330732736).

Almost surely, 2^661465471 is an apocalyptic number.

661465471 is a deficient number, since it is larger than the sum of its proper divisors (1).

661465471 is an equidigital number, since it uses as much as digits as its factorization.

661465471 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 120960, while the sum is 40.

The square root of 661465471 is about 25718.9710330721. The cubic root of 661465471 is about 871.3026994108.

It can be divided in two parts, 66146 and 5471, that added together give a palindrome (71617).

The spelling of 661465471 in words is "six hundred sixty-one million, four hundred sixty-five thousand, four hundred seventy-one".