421505251 has 2 divisors, whose sum is σ = 421505252. Its totient is φ = 421505250.

The previous prime is 421505239. The next prime is 421505257. The reversal of 421505251 is 152505124.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 421505251 - 2²⁵ = 387950819 is a prime.

It is not a weakly prime, because it can be changed into another prime (421505257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210752625 + 210752626.

It is an arithmetic number, because the mean of its divisors is an integer number (210752626).

Almost surely, 2^421505251 is an apocalyptic number.

421505251 is a deficient number, since it is larger than the sum of its proper divisors (1).

421505251 is an equidigital number, since it uses as much as digits as its factorization.

421505251 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2000, while the sum is 25.

The square root of 421505251 is about 20530.5930503724. The cubic root of 421505251 is about 749.7808254377.

The spelling of 421505251 in words is "four hundred twenty-one million, five hundred five thousand, two hundred fifty-one".