66421357 has 2 divisors, whose sum is σ = 66421358. Its totient is φ = 66421356.

The previous prime is 66421343. The next prime is 66421373. The reversal of 66421357 is 75312466.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64818601 + 1602756 = 8051^2 + 1266^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66421357 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66421307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33210678 + 33210679.

It is an arithmetic number, because the mean of its divisors is an integer number (33210679).

Almost surely, 2^66421357 is an apocalyptic number.

It is an amenable number.

66421357 is a deficient number, since it is larger than the sum of its proper divisors (1).

66421357 is an equidigital number, since it uses as much as digits as its factorization.

66421357 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30240, while the sum is 34.

The square root of 66421357 is about 8149.9298769989. The cubic root of 66421357 is about 404.9821807940.

The spelling of 66421357 in words is "sixty-six million, four hundred twenty-one thousand, three hundred fifty-seven".