991620060845 has 8 divisors (see below), whose sum is σ = 1222104723864. Its totient is φ = 771855614784.

The previous prime is 991620060839. The next prime is 991620060881. The reversal of 991620060845 is 548060026199.

It can be written as a sum of positive squares in 4 ways, for example, as 552765484324 + 438854576521 = 743482^2 + 662461^2 .

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 991620060845 - 2¹⁰ = 991620059821 is a prime.

It is a super-2 number, since 2×991620060845² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 991620060793 and 991620060802.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2680054034 + ... + 2680054403.

It is an arithmetic number, because the mean of its divisors is an integer number (152763090483).

Almost surely, 2^991620060845 is an apocalyptic number.

It is an amenable number.

991620060845 is a deficient number, since it is larger than the sum of its proper divisors (230484663019).

991620060845 is a wasteful number, since it uses less digits than its factorization.

991620060845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5360108479.

The product of its (nonzero) digits is 933120, while the sum is 50.

The spelling of 991620060845 in words is "nine hundred ninety-one billion, six hundred twenty million, sixty thousand, eight hundred forty-five".