667288335697981 has 4 divisors (see below), whose sum is σ = 667402188004764. Its totient is φ = 667174483391200.

The previous prime is 667288335697927. The next prime is 667288335697999. The reversal of 667288335697981 is 189796533882766.

It is a happy number.

667288335697981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 557567110153881 + 109721225544100 = 23612859^2 + 10474790^2 .

It is a cyclic number.

It is not a de Polignac number, because 667288335697981 - 2⁷ = 667288335697853 is a prime.

It is a super-2 number, since 2×667288335697981² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 667288335697892 and 667288335697901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667288335697681) 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, 56926144600 + ... + 56926156321.

It is an arithmetic number, because the mean of its divisors is an integer number (166850547001191).

Almost surely, 2^{667288335697981} is an apocalyptic number.

It is an amenable number.

667288335697981 is a deficient number, since it is larger than the sum of its proper divisors (113852306783).

667288335697981 is a wasteful number, since it uses less digits than its factorization.

667288335697981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113852306782.

The product of its digits is 39504568320, while the sum is 88.

The spelling of 667288335697981 in words is "six hundred sixty-seven trillion, two hundred eighty-eight billion, three hundred thirty-five million, six hundred ninety-seven thousand, nine hundred eighty-one".