991948273156 has 81 divisors (see below), whose sum is σ = 1832403682431. Its totient is φ = 469840984704.

The previous prime is 991948273153. The next prime is 991948273231. The reversal of 991948273156 is 651372849199.

The square root of 991948273156 is 995966.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 60877666756 + 931070606400 = 246734^2 + 964920^2 .

It is a super-2 number, since 2×991948273156² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (991948273153) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 3169163656 + ... + 3169163968.

Almost surely, 2^991948273156 is an apocalyptic number.

991948273156 is the 995966-th square number.

It is an amenable number.

991948273156 is a deficient number, since it is larger than the sum of its proper divisors (840455409275).

991948273156 is an equidigital number, since it uses as much as digits as its factorization.

991948273156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 790 (or 395 counting only the distinct ones).

The product of its digits is 29393280, while the sum is 64.

Multiplying 991948273156 by its sum of digits (64), we get a square (63484689481984 = 7967728²).

The spelling of 991948273156 in words is "nine hundred ninety-one billion, nine hundred forty-eight million, two hundred seventy-three thousand, one hundred fifty-six".