1991964519 has 24 divisors (see below), whose sum is σ = 3024339552. Its totient is φ = 1260948480.

The previous prime is 1991964517. The next prime is 1991964529. The reversal of 1991964519 is 9154691991.

It is a happy number.

1991964519 is a `hidden beast` number, since 19 + 91 + 96 + 451 + 9 = 666.

It is not a de Polignac number, because 1991964519 - 2¹ = 1991964517 is a prime.

It is a super-2 number, since 2×1991964519² = 7935845289909802722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1991964517) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6762 + ... + 63479.

It is an arithmetic number, because the mean of its divisors is an integer number (126014148).

Almost surely, 2^1991964519 is an apocalyptic number.

1991964519 is a deficient number, since it is larger than the sum of its proper divisors (1032375033).

1991964519 is a wasteful number, since it uses less digits than its factorization.

1991964519 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70407 (or 70404 counting only the distinct ones).

The product of its digits is 787320, while the sum is 54.

The square root of 1991964519 is about 44631.4297216659. The cubic root of 1991964519 is about 1258.2314397892.

The spelling of 1991964519 in words is "one billion, nine hundred ninety-one million, nine hundred sixty-four thousand, five hundred nineteen".