664444354551 has 4 divisors (see below), whose sum is σ = 885925806072. Its totient is φ = 442962903032.

The previous prime is 664444354549. The next prime is 664444354571. The reversal of 664444354551 is 155453444466.

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

It is a cyclic number.

It is not a de Polignac number, because 664444354551 - 2¹ = 664444354549 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 664444354494 and 664444354503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664444354571) 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, 110740725756 + ... + 110740725761.

It is an arithmetic number, because the mean of its divisors is an integer number (221481451518).

Almost surely, 2^664444354551 is an apocalyptic number.

664444354551 is a deficient number, since it is larger than the sum of its proper divisors (221481451521).

664444354551 is a wasteful number, since it uses less digits than its factorization.

664444354551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221481451520.

The product of its digits is 13824000, while the sum is 51.

The spelling of 664444354551 in words is "six hundred sixty-four billion, four hundred forty-four million, three hundred fifty-four thousand, five hundred fifty-one".