64687029509 has 2 divisors, whose sum is σ = 64687029510. Its totient is φ = 64687029508.

The previous prime is 64687029479. The next prime is 64687029599. The reversal of 64687029509 is 90592078646.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50757837025 + 13929192484 = 225295^2 + 118022^2 .

It is a cyclic number.

It is not a de Polignac number, because 64687029509 - 2¹² = 64687025413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64687029599) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32343514754 + 32343514755.

It is an arithmetic number, because the mean of its divisors is an integer number (32343514755).

Almost surely, 2^64687029509 is an apocalyptic number.

It is an amenable number.

64687029509 is a deficient number, since it is larger than the sum of its proper divisors (1).

64687029509 is an equidigital number, since it uses as much as digits as its factorization.

64687029509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6531840, while the sum is 56.

The spelling of 64687029509 in words is "sixty-four billion, six hundred eighty-seven million, twenty-nine thousand, five hundred nine".