646620420 has 24 divisors (see below), whose sum is σ = 1810537344. Its totient is φ = 172432096.

The previous prime is 646620397. The next prime is 646620431. The reversal of 646620420 is 24026646.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

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, 5388444 + ... + 5388563.

It is an arithmetic number, because the mean of its divisors is an integer number (75439056).

Almost surely, 2^646620420 is an apocalyptic number.

646620420 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

646620420 is an abundant number, since it is smaller than the sum of its proper divisors (1163916924).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

646620420 is a wasteful number, since it uses less digits than its factorization.

646620420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10777019 (or 10777017 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 30.

The square root of 646620420 is about 25428.7321744518. The cubic root of 646620420 is about 864.7352013372.

The spelling of 646620420 in words is "six hundred forty-six million, six hundred twenty thousand, four hundred twenty".