387815898121 has 4 divisors (see below), whose sum is σ = 408227261200. Its totient is φ = 367404535044.

The previous prime is 387815898073. The next prime is 387815898131. The reversal of 387815898121 is 121898518783.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 121898518783 = 673 ⋅181127071.

It is a cyclic number.

It is not a de Polignac number, because 387815898121 - 2⁷ = 387815897993 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 387815898121.

It is not an unprimeable number, because it can be changed into a prime (387815898131) 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, 10205681511 + ... + 10205681548.

It is an arithmetic number, because the mean of its divisors is an integer number (102056815300).

Almost surely, 2^387815898121 is an apocalyptic number.

It is an amenable number.

387815898121 is a deficient number, since it is larger than the sum of its proper divisors (20411363079).

387815898121 is a wasteful number, since it uses less digits than its factorization.

387815898121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20411363078.

The product of its digits is 7741440, while the sum is 61.

The spelling of 387815898121 in words is "three hundred eighty-seven billion, eight hundred fifteen million, eight hundred ninety-eight thousand, one hundred twenty-one".