429981661 has 2 divisors, whose sum is σ = 429981662. Its totient is φ = 429981660.

The previous prime is 429981659. The next prime is 429981677. The reversal of 429981661 is 166189924.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 428738436 + 1243225 = 20706^2 + 1115^2 .

It is a cyclic number.

It is not a de Polignac number, because 429981661 - 2¹ = 429981659 is a prime.

Together with 429981659, it forms a pair of twin primes.

It is a nialpdrome in base 12.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (429981691) 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, 214990830 + 214990831.

It is an arithmetic number, because the mean of its divisors is an integer number (214990831).

Almost surely, 2^429981661 is an apocalyptic number.

It is an amenable number.

429981661 is a deficient number, since it is larger than the sum of its proper divisors (1).

429981661 is an equidigital number, since it uses as much as digits as its factorization.

429981661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 186624, while the sum is 46.

The square root of 429981661 is about 20735.9991560571. Note that the first 3 decimals coincide. The cubic root of 429981661 is about 754.7735010529.

The spelling of 429981661 in words is "four hundred twenty-nine million, nine hundred eighty-one thousand, six hundred sixty-one".