64687028981 has 2 divisors, whose sum is σ = 64687028982. Its totient is φ = 64687028980.

The previous prime is 64687028977. The next prime is 64687029013. The reversal of 64687028981 is 18982078646.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 35056570756 + 29630458225 = 187234^2 + 172135^2 .

It is a cyclic number.

It is not a de Polignac number, because 64687028981 - 2² = 64687028977 is a prime.

It is a super-2 number, since 2×64687028981² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 64687028981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64687028381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32343514490 + 32343514491.

It is an arithmetic number, because the mean of its divisors is an integer number (32343514491).

Almost surely, 2^64687028981 is an apocalyptic number.

It is an amenable number.

64687028981 is a deficient number, since it is larger than the sum of its proper divisors (1).

64687028981 is an equidigital number, since it uses as much as digits as its factorization.

64687028981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9289728, while the sum is 59.

The spelling of 64687028981 in words is "sixty-four billion, six hundred eighty-seven million, twenty-eight thousand, nine hundred eighty-one".