420821247 has 64 divisors (see below), whose sum is σ = 748735488. Its totient is φ = 203520000.

The previous prime is 420821243. The next prime is 420821251. The reversal of 420821247 is 742128024.

It is an interprime number because it is at equal distance from previous prime (420821243) and next prime (420821251).

It is not a de Polignac number, because 420821247 - 2² = 420821243 is a prime.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (420821243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 396097 + ... + 397157.

It is an arithmetic number, because the mean of its divisors is an integer number (11698992).

Almost surely, 2^420821247 is an apocalyptic number.

420821247 is a deficient number, since it is larger than the sum of its proper divisors (327914241).

420821247 is a wasteful number, since it uses less digits than its factorization.

420821247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1200.

The product of its (nonzero) digits is 7168, while the sum is 30.

The square root of 420821247 is about 20513.9281221320. The cubic root of 420821247 is about 749.3750331443.

The spelling of 420821247 in words is "four hundred twenty million, eight hundred twenty-one thousand, two hundred forty-seven".