421521029 has 2 divisors, whose sum is σ = 421521030. Its totient is φ = 421521028.

The previous prime is 421521019. The next prime is 421521047. The reversal of 421521029 is 920125124.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 404090404 + 17430625 = 20102^2 + 4175^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-421521029 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 421520989 and 421521007.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (421521019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210760514 + 210760515.

It is an arithmetic number, because the mean of its divisors is an integer number (210760515).

Almost surely, 2^421521029 is an apocalyptic number.

It is an amenable number.

421521029 is a deficient number, since it is larger than the sum of its proper divisors (1).

421521029 is an equidigital number, since it uses as much as digits as its factorization.

421521029 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 421521029 is about 20530.9773026030. The cubic root of 421521029 is about 749.7901807140.

The spelling of 421521029 in words is "four hundred twenty-one million, five hundred twenty-one thousand, twenty-nine".