664321560006251 has 4 divisors (see below), whose sum is σ = 759224640007152. Its totient is φ = 569418480005352.

The previous prime is 664321560006239. The next prime is 664321560006277. The reversal of 664321560006251 is 152600065123466.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-664321560006251 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 664321560006196 and 664321560006205.

It is not an unprimeable number, because it can be changed into a prime (664321560008251) 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, 47451540000440 + ... + 47451540000453.

It is an arithmetic number, because the mean of its divisors is an integer number (189806160001788).

Almost surely, 2^{664321560006251} is an apocalyptic number.

664321560006251 is a deficient number, since it is larger than the sum of its proper divisors (94903080000901).

664321560006251 is an equidigital number, since it uses as much as digits as its factorization.

664321560006251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94903080000900.

The product of its (nonzero) digits is 1555200, while the sum is 47.

The spelling of 664321560006251 in words is "six hundred sixty-four trillion, three hundred twenty-one billion, five hundred sixty million, six thousand, two hundred fifty-one".