991139609461 has 8 divisors (see below), whose sum is σ = 991735082624. Its totient is φ = 990544282560.

The previous prime is 991139609443. The next prime is 991139609479. The reversal of 991139609461 is 164906931199.

It is an interprime number because it is at equal distance from previous prime (991139609443) and next prime (991139609479).

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 991139609461 - 2¹¹ = 991139607413 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 991139609396 and 991139609405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991139609441) 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, 15434941 + ... + 15499021.

It is an arithmetic number, because the mean of its divisors is an integer number (123966885328).

Almost surely, 2^991139609461 is an apocalyptic number.

It is an amenable number.

991139609461 is a deficient number, since it is larger than the sum of its proper divisors (595473163).

991139609461 is a wasteful number, since it uses less digits than its factorization.

991139609461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73131.

The product of its (nonzero) digits is 2834352, while the sum is 58.

The spelling of 991139609461 in words is "nine hundred ninety-one billion, one hundred thirty-nine million, six hundred nine thousand, four hundred sixty-one".