421552421 has 2 divisors, whose sum is σ = 421552422. Its totient is φ = 421552420.

The previous prime is 421552363. The next prime is 421552423. The reversal of 421552421 is 124255124.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 403447396 + 18105025 = 20086^2 + 4255^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-421552421 is a prime.

It is a super-2 number, since 2×421552421² = 355412887301922482, which contains 22 as substring.

Together with 421552423, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (421552423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210776210 + 210776211.

It is an arithmetic number, because the mean of its divisors is an integer number (210776211).

Almost surely, 2^421552421 is an apocalyptic number.

It is an amenable number.

421552421 is a deficient number, since it is larger than the sum of its proper divisors (1).

421552421 is an equidigital number, since it uses as much as digits as its factorization.

421552421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3200, while the sum is 26.

The square root of 421552421 is about 20531.7417916747. The cubic root of 421552421 is about 749.8087933316.

The spelling of 421552421 in words is "four hundred twenty-one million, five hundred fifty-two thousand, four hundred twenty-one".