387399657581 has 2 divisors, whose sum is σ = 387399657582. Its totient is φ = 387399657580.

The previous prime is 387399657577. The next prime is 387399657637. The reversal of 387399657581 is 185756993783.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 330700904356 + 56698753225 = 575066^2 + 238115^2 .

It is a cyclic number.

It is not a de Polignac number, because 387399657581 - 2² = 387399657577 is a prime.

It is a super-2 number, since 2×387399657581² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (387399657551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 193699828790 + 193699828791.

It is an arithmetic number, because the mean of its divisors is an integer number (193699828791).

Almost surely, 2^387399657581 is an apocalyptic number.

It is an amenable number.

387399657581 is a deficient number, since it is larger than the sum of its proper divisors (1).

387399657581 is an equidigital number, since it uses as much as digits as its factorization.

387399657581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 342921600, while the sum is 71.

The spelling of 387399657581 in words is "three hundred eighty-seven billion, three hundred ninety-nine million, six hundred fifty-seven thousand, five hundred eighty-one".