991200312333131 has 4 divisors (see below), whose sum is σ = 994583248552992. Its totient is φ = 987817376113272.

The previous prime is 991200312333103. The next prime is 991200312333227. The reversal of 991200312333131 is 131333213002199.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 991200312333131 - 2¹⁰ = 991200312332107 is a prime.

It is a super-2 number, since 2×991200312333131² (a number of 31 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (991200312333031) 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, 1691468109491 + ... + 1691468110076.

It is an arithmetic number, because the mean of its divisors is an integer number (248645812138248).

Almost surely, 2^{991200312333131} is an apocalyptic number.

991200312333131 is a deficient number, since it is larger than the sum of its proper divisors (3382936219861).

991200312333131 is a wasteful number, since it uses less digits than its factorization.

991200312333131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3382936219860.

The product of its (nonzero) digits is 78732, while the sum is 41.

The spelling of 991200312333131 in words is "nine hundred ninety-one trillion, two hundred billion, three hundred twelve million, three hundred thirty-three thousand, one hundred thirty-one".