66320401 has 4 divisors (see below), whose sum is σ = 75794752. Its totient is φ = 56846052.

The previous prime is 66320399. The next prime is 66320407. The reversal of 66320401 is 10402366.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66320401 - 2¹ = 66320399 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66320407) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4737165 + ... + 4737178.

It is an arithmetic number, because the mean of its divisors is an integer number (18948688).

Almost surely, 2^66320401 is an apocalyptic number.

It is an amenable number.

66320401 is a deficient number, since it is larger than the sum of its proper divisors (9474351).

66320401 is an equidigital number, since it uses as much as digits as its factorization.

66320401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9474350.

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 66320401 is about 8143.7338487944. The cubic root of 66320401 is about 404.7768948501.

Adding to 66320401 its reverse (10402366), we get a palindrome (76722767).

The spelling of 66320401 in words is "sixty-six million, three hundred twenty thousand, four hundred one".