1991513383 has 8 divisors (see below), whose sum is σ = 2000610320. Its totient is φ = 1982430720.

The previous prime is 1991513347. The next prime is 1991513387. The reversal of 1991513383 is 3833151991.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1991513383 - 2¹⁷ = 1991382311 is a prime.

It is a super-2 number, since 2×1991513383² = 7932251109336209378, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1991513387) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 354823 + ... + 360391.

It is an arithmetic number, because the mean of its divisors is an integer number (250076290).

Almost surely, 2^1991513383 is an apocalyptic number.

1991513383 is a deficient number, since it is larger than the sum of its proper divisors (9096937).

1991513383 is a wasteful number, since it uses less digits than its factorization.

1991513383 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7137.

The product of its digits is 87480, while the sum is 43.

The square root of 1991513383 is about 44626.3754185795. The cubic root of 1991513383 is about 1258.1364454003.

The spelling of 1991513383 in words is "one billion, nine hundred ninety-one million, five hundred thirteen thousand, three hundred eighty-three".