431451661 has 2 divisors, whose sum is σ = 431451662. Its totient is φ = 431451660.

The previous prime is 431451623. The next prime is 431451667. The reversal of 431451661 is 166154134.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 416935561 + 14516100 = 20419^2 + 3810^2 .

It is a cyclic number.

It is not a de Polignac number, because 431451661 - 2²¹ = 429354509 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (431451667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 215725830 + 215725831.

It is an arithmetic number, because the mean of its divisors is an integer number (215725831).

Almost surely, 2^431451661 is an apocalyptic number.

It is an amenable number.

431451661 is a deficient number, since it is larger than the sum of its proper divisors (1).

431451661 is an equidigital number, since it uses as much as digits as its factorization.

431451661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8640, while the sum is 31.

The square root of 431451661 is about 20771.4145161084. The cubic root of 431451661 is about 755.6326501406.

The spelling of 431451661 in words is "four hundred thirty-one million, four hundred fifty-one thousand, six hundred sixty-one".