421365661 has 2 divisors, whose sum is σ = 421365662. Its totient is φ = 421365660.

The previous prime is 421365653. The next prime is 421365667. The reversal of 421365661 is 166563124.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 309408100 + 111957561 = 17590^2 + 10581^2 .

It is a cyclic number.

It is not a de Polignac number, because 421365661 - 2³ = 421365653 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (421365667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210682830 + 210682831.

It is an arithmetic number, because the mean of its divisors is an integer number (210682831).

Almost surely, 2^421365661 is an apocalyptic number.

It is an amenable number.

421365661 is a deficient number, since it is larger than the sum of its proper divisors (1).

421365661 is an equidigital number, since it uses as much as digits as its factorization.

421365661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 25920, while the sum is 34.

The square root of 421365661 is about 20527.1932080350. The cubic root of 421365661 is about 749.6980479311.

The spelling of 421365661 in words is "four hundred twenty-one million, three hundred sixty-five thousand, six hundred sixty-one".