666625212 has 36 divisors (see below), whose sum is σ = 1838270616. Its totient is φ = 202007520.

The previous prime is 666625121. The next prime is 666625313. The reversal of 666625212 is 212526666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 841303 + ... + 842094.

Almost surely, 2^666625212 is an apocalyptic number.

It is an amenable number.

666625212 is an abundant number, since it is smaller than the sum of its proper divisors (1171645404).

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

666625212 is a wasteful number, since it uses less digits than its factorization.

666625212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1683418 (or 1683413 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

The square root of 666625212 is about 25819.0861960682. The cubic root of 666625212 is about 873.5623573675.

It can be divided in two parts, 6666 and 25212, that added together give a triangular number (31878 = T₂₅₂).

The spelling of 666625212 in words is "six hundred sixty-six million, six hundred twenty-five thousand, two hundred twelve".