1991883615 has 16 divisors (see below), whose sum is σ = 3194594016. Its totient is φ = 1059811200.

The previous prime is 1991883587. The next prime is 1991883623. The reversal of 1991883615 is 5163881991.

It is not a de Polignac number, because 1991883615 - 2¹³ = 1991875423 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 151396 + ... + 164025.

It is an arithmetic number, because the mean of its divisors is an integer number (199662126).

Almost surely, 2^1991883615 is an apocalyptic number.

1991883615 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1991883615 is a deficient number, since it is larger than the sum of its proper divisors (1202710401).

1991883615 is a wasteful number, since it uses less digits than its factorization.

1991883615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 315850.

The product of its digits is 466560, while the sum is 51.

The square root of 1991883615 is about 44630.5233556587. The cubic root of 1991883615 is about 1258.2144051259.

The spelling of 1991883615 in words is "one billion, nine hundred ninety-one million, eight hundred eighty-three thousand, six hundred fifteen".