99991963 has 4 divisors (see below), whose sum is σ = 100663200. Its totient is φ = 99320728.

The previous prime is 99991951. The next prime is 99991981. The reversal of 99991963 is 36919999.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99991963 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99991933) 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, 335395 + ... + 335692.

It is an arithmetic number, because the mean of its divisors is an integer number (25165800).

Almost surely, 2^99991963 is an apocalyptic number.

99991963 is a deficient number, since it is larger than the sum of its proper divisors (671237).

99991963 is a wasteful number, since it uses less digits than its factorization.

99991963 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 671236.

The product of its digits is 1062882, while the sum is 55.

The square root of 99991963 is about 9999.5981419255. The cubic root of 99991963 is about 464.1464482116.

The spelling of 99991963 in words is "ninety-nine million, nine hundred ninety-one thousand, nine hundred sixty-three".