660333421 has 12 divisors (see below), whose sum is σ = 728441532. Its totient is φ = 598136000.

The previous prime is 660333389. The next prime is 660333437. The reversal of 660333421 is 124333066.

It can be written as a sum of positive squares in 2 ways, for example, as 571879396 + 88454025 = 23914^2 + 9405^2 .

It is not a de Polignac number, because 660333421 - 2⁵ = 660333389 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 660333421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660333461) by changing a digit.

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, 24291 + ... + 43711.

It is an arithmetic number, because the mean of its divisors is an integer number (60703461).

Almost surely, 2^660333421 is an apocalyptic number.

It is an amenable number.

660333421 is a deficient number, since it is larger than the sum of its proper divisors (68108111).

660333421 is a wasteful number, since it uses less digits than its factorization.

660333421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19724 (or 19713 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 28.

The square root of 660333421 is about 25696.9535353901. The cubic root of 660333421 is about 870.8053585350.

Adding to 660333421 its reverse (124333066), we get a palindrome (784666487).

The spelling of 660333421 in words is "six hundred sixty million, three hundred thirty-three thousand, four hundred twenty-one".