99991156 has 6 divisors (see below), whose sum is σ = 174984530. Its totient is φ = 49995576.

The previous prime is 99991109. The next prime is 99991207. The reversal of 99991156 is 65119999.

It can be written as a sum of positive squares in only one way, i.e., 98327056 + 1664100 = 9916^2 + 1290^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12498891 + ... + 12498898.

Almost surely, 2^99991156 is an apocalyptic number.

It is an amenable number.

99991156 is a deficient number, since it is larger than the sum of its proper divisors (74993374).

99991156 is a wasteful number, since it uses less digits than its factorization.

99991156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24997793 (or 24997791 counting only the distinct ones).

The product of its digits is 196830, while the sum is 49.

The square root of 99991156 is about 9999.5577902225. The cubic root of 99991156 is about 464.1451995540.

The spelling of 99991156 in words is "ninety-nine million, nine hundred ninety-one thousand, one hundred fifty-six".