666783420 has 48 divisors (see below), whose sum is σ = 1870404480. Its totient is φ = 177484096.

The previous prime is 666783419. The next prime is 666783427. The reversal of 666783420 is 24387666.

It is a super-3 number, since 3×666783420³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666783427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23911 + ... + 43649.

It is an arithmetic number, because the mean of its divisors is an integer number (38966760).

Almost surely, 2^666783420 is an apocalyptic number.

666783420 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

666783420 is an abundant number, since it is smaller than the sum of its proper divisors (1203621060).

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

666783420 is a wasteful number, since it uses less digits than its factorization.

666783420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20314 (or 20312 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 42.

The square root of 666783420 is about 25822.1497943142. The cubic root of 666783420 is about 873.6314584752.

The spelling of 666783420 in words is "six hundred sixty-six million, seven hundred eighty-three thousand, four hundred twenty".