666232021 has 8 divisors (see below), whose sum is σ = 819977984. Its totient is φ = 527128560.

The previous prime is 666232013. The next prime is 666232033. The reversal of 666232021 is 120232666.

It is a happy number.

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

It is not a de Polignac number, because 666232021 - 2³ = 666232013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666242021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3660525 + ... + 3660706.

It is an arithmetic number, because the mean of its divisors is an integer number (102497248).

Almost surely, 2^666232021 is an apocalyptic number.

It is an amenable number.

666232021 is a deficient number, since it is larger than the sum of its proper divisors (153745963).

666232021 is a wasteful number, since it uses less digits than its factorization.

666232021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7321251.

The product of its (nonzero) digits is 5184, while the sum is 28.

The square root of 666232021 is about 25811.4707252415. The cubic root of 666232021 is about 873.3905744811.

Adding to 666232021 its reverse (120232666), we get a palindrome (786464687).

It can be divided in two parts, 66623 and 2021, that added together give a square (68644 = 262²).

The spelling of 666232021 in words is "six hundred sixty-six million, two hundred thirty-two thousand, twenty-one".