66732021 has 12 divisors (see below), whose sum is σ = 102060972. Its totient is φ = 41870976.

The previous prime is 66732007. The next prime is 66732041. The reversal of 66732021 is 12023766.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 36360900 + 30371121 = 6030^2 + 5511^2 .

It is not a de Polignac number, because 66732021 - 2⁵ = 66731989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66732041) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 217926 + ... + 218231.

It is an arithmetic number, because the mean of its divisors is an integer number (8505081).

Almost surely, 2^66732021 is an apocalyptic number.

It is an amenable number.

66732021 is a deficient number, since it is larger than the sum of its proper divisors (35328951).

66732021 is a wasteful number, since it uses less digits than its factorization.

66732021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 436180 (or 436177 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 27.

The square root of 66732021 is about 8168.9669481520. The cubic root of 66732021 is about 405.6125891836.

Adding to 66732021 its reverse (12023766), we get a palindrome (78755787).

The spelling of 66732021 in words is "sixty-six million, seven hundred thirty-two thousand, twenty-one".