1993387851 has 144 divisors (see below), whose sum is σ = 3826158336. Its totient is φ = 973171584.

The previous prime is 1993387849. The next prime is 1993387871. The reversal of 1993387851 is 1587833991.

1993387851 is a `hidden beast` number, since 199 + 338 + 78 + 51 = 666.

It is not a de Polignac number, because 1993387851 - 2¹ = 1993387849 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1993387841) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 18629740 + ... + 18629846.

It is an arithmetic number, because the mean of its divisors is an integer number (26570544).

Almost surely, 2^1993387851 is an apocalyptic number.

1993387851 is a deficient number, since it is larger than the sum of its proper divisors (1832770485).

1993387851 is a wasteful number, since it uses less digits than its factorization.

1993387851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222 (or 196 counting only the distinct ones).

The product of its digits is 1632960, while the sum is 54.

The square root of 1993387851 is about 44647.3722743008. The cubic root of 1993387851 is about 1258.5310526711.

The spelling of 1993387851 in words is "one billion, nine hundred ninety-three million, three hundred eighty-seven thousand, eight hundred fifty-one".