1993305881 has 4 divisors (see below), whose sum is σ = 2278063872. Its totient is φ = 1708547892.

The previous prime is 1993305863. The next prime is 1993305887. The reversal of 1993305881 is 1885033991.

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.

It is a cyclic number.

It is not a de Polignac number, because 1993305881 - 2³⁰ = 919564057 is a prime.

It is a super-2 number, since 2×1993305881² = 7946536670458372322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1993305887) 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, 142378985 + ... + 142378998.

It is an arithmetic number, because the mean of its divisors is an integer number (569515968).

Almost surely, 2^1993305881 is an apocalyptic number.

It is an amenable number.

1993305881 is a deficient number, since it is larger than the sum of its proper divisors (284757991).

1993305881 is an equidigital number, since it uses as much as digits as its factorization.

1993305881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 284757990.

The product of its (nonzero) digits is 233280, while the sum is 47.

The square root of 1993305881 is about 44646.4542937062. The cubic root of 1993305881 is about 1258.5138017710.

The spelling of 1993305881 in words is "one billion, nine hundred ninety-three million, three hundred five thousand, eight hundred eighty-one".