406623661 has 2 divisors, whose sum is σ = 406623662. Its totient is φ = 406623660.

The previous prime is 406623643. The next prime is 406623689. The reversal of 406623661 is 166326604.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 397204900 + 9418761 = 19930^2 + 3069^2 .

It is a cyclic number.

It is not a de Polignac number, because 406623661 - 2¹⁷ = 406492589 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (406623611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 203311830 + 203311831.

It is an arithmetic number, because the mean of its divisors is an integer number (203311831).

Almost surely, 2^406623661 is an apocalyptic number.

It is an amenable number.

406623661 is a deficient number, since it is larger than the sum of its proper divisors (1).

406623661 is an equidigital number, since it uses as much as digits as its factorization.

406623661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31104, while the sum is 34.

The square root of 406623661 is about 20164.9116288666. The cubic root of 406623661 is about 740.8510181330.

The spelling of 406623661 in words is "four hundred six million, six hundred twenty-three thousand, six hundred sixty-one".