1661646229 has 2 divisors, whose sum is σ = 1661646230. Its totient is φ = 1661646228.

The previous prime is 1661646223. The next prime is 1661646277. The reversal of 1661646229 is 9226461661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1605845329 + 55800900 = 40073^2 + 7470^2 .

It is a cyclic number.

It is not a de Polignac number, because 1661646229 - 2⁷ = 1661646101 is a prime.

It is a super-2 number, since 2×1661646229² = 5522136380699840882, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1661646223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830823114 + 830823115.

It is an arithmetic number, because the mean of its divisors is an integer number (830823115).

Almost surely, 2^1661646229 is an apocalyptic number.

It is an amenable number.

1661646229 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661646229 is an equidigital number, since it uses as much as digits as its factorization.

1661646229 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 186624, while the sum is 43.

The square root of 1661646229 is about 40763.2951195067. The cubic root of 1661646229 is about 1184.4394267406.

The spelling of 1661646229 in words is "one billion, six hundred sixty-one million, six hundred forty-six thousand, two hundred twenty-nine".