420840993 has 8 divisors (see below), whose sum is σ = 564256800. Its totient is φ = 278992928.

The previous prime is 420840989. The next prime is 420841019. The reversal of 420840993 is 399048024.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 420840993 - 2² = 420840989 is a prime.

It is not an unprimeable number, because it can be changed into a prime (420840943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 391308 + ... + 392381.

It is an arithmetic number, because the mean of its divisors is an integer number (70532100).

Almost surely, 2^420840993 is an apocalyptic number.

It is an amenable number.

420840993 is a deficient number, since it is larger than the sum of its proper divisors (143415807).

420840993 is a wasteful number, since it uses less digits than its factorization.

420840993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 783871.

The product of its (nonzero) digits is 62208, while the sum is 39.

The square root of 420840993 is about 20514.4093992491. The cubic root of 420840993 is about 749.3867538199.

The spelling of 420840993 in words is "four hundred twenty million, eight hundred forty thousand, nine hundred ninety-three".