420173721 has 48 divisors (see below), whose sum is σ = 707166720. Its totient is φ = 237888000.

The previous prime is 420173713. The next prime is 420173773. The reversal of 420173721 is 127371024.

It is a happy number.

420173721 is a `hidden beast` number, since 420 + 173 + 72 + 1 = 666.

It is not a de Polignac number, because 420173721 - 2³ = 420173713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (420173321) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 86641 + ... + 91361.

It is an arithmetic number, because the mean of its divisors is an integer number (14732640).

Almost surely, 2^420173721 is an apocalyptic number.

It is an amenable number.

420173721 is a deficient number, since it is larger than the sum of its proper divisors (286992999).

420173721 is a wasteful number, since it uses less digits than its factorization.

420173721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4798 (or 4795 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 27.

The square root of 420173721 is about 20498.1394521552. The cubic root of 420173721 is about 748.9904764259.

The spelling of 420173721 in words is "four hundred twenty million, one hundred seventy-three thousand, seven hundred twenty-one".