421657673 has 2 divisors, whose sum is σ = 421657674. Its totient is φ = 421657672.

The previous prime is 421657669. The next prime is 421657741. The reversal of 421657673 is 376756124.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 268566544 + 153091129 = 16388^2 + 12373^2 .

It is a cyclic number.

It is not a de Polignac number, because 421657673 - 2² = 421657669 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 421657673.

It is not a weakly prime, because it can be changed into another prime (421657603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210828836 + 210828837.

It is an arithmetic number, because the mean of its divisors is an integer number (210828837).

Almost surely, 2^421657673 is an apocalyptic number.

It is an amenable number.

421657673 is a deficient number, since it is larger than the sum of its proper divisors (1).

421657673 is an equidigital number, since it uses as much as digits as its factorization.

421657673 is an evil number, because the sum of its binary digits is even.

The product of its digits is 211680, while the sum is 41.

The square root of 421657673 is about 20534.3047849203. The cubic root of 421657673 is about 749.8711915087.

The spelling of 421657673 in words is "four hundred twenty-one million, six hundred fifty-seven thousand, six hundred seventy-three".