660307421 has 8 divisors (see below), whose sum is σ = 706358520. Its totient is φ = 615057408.

The previous prime is 660307343. The next prime is 660307423. The reversal of 660307421 is 124703066.

It can be written as a sum of positive squares in 4 ways, for example, as 207043321 + 453264100 = 14389^2 + 21290^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-660307421 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660307423) 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, 198566 + ... + 201863.

It is an arithmetic number, because the mean of its divisors is an integer number (88294815).

Almost surely, 2^660307421 is an apocalyptic number.

It is an amenable number.

660307421 is a deficient number, since it is larger than the sum of its proper divisors (46051099).

660307421 is a wasteful number, since it uses less digits than its factorization.

660307421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 400543.

The product of its (nonzero) digits is 6048, while the sum is 29.

The square root of 660307421 is about 25696.4476338657. The cubic root of 660307421 is about 870.7939293409.

The spelling of 660307421 in words is "six hundred sixty million, three hundred seven thousand, four hundred twenty-one".