420621993 has 48 divisors (see below), whose sum is σ = 684028800. Its totient is φ = 246854400.

The previous prime is 420621979. The next prime is 420622009. The reversal of 420621993 is 399126024.

420621993 is a `hidden beast` number, since 4 + 20 + 621 + 9 + 9 + 3 = 666.

It is not a de Polignac number, because 420621993 - 2⁵ = 420621961 is a prime.

It is not an unprimeable number, because it can be changed into a prime (420621893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 701908 + ... + 702506.

It is an arithmetic number, because the mean of its divisors is an integer number (14250600).

Almost surely, 2^420621993 is an apocalyptic number.

It is an amenable number.

420621993 is a deficient number, since it is larger than the sum of its proper divisors (263406807).

420621993 is a wasteful number, since it uses less digits than its factorization.

420621993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 830 (or 827 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

The square root of 420621993 is about 20509.0709930996. The cubic root of 420621993 is about 749.2567409981.

The spelling of 420621993 in words is "four hundred twenty million, six hundred twenty-one thousand, nine hundred ninety-three".