991601828744 has 8 divisors (see below), whose sum is σ = 1859253428910. Its totient is φ = 495800914368.

The previous prime is 991601828743. The next prime is 991601828753. The reversal of 991601828744 is 447828106199.

It can be written as a sum of positive squares in only one way, i.e., 708226599844 + 283375228900 = 841562^2 + 532330^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (991601828743) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61975114289 + ... + 61975114304.

Almost surely, 2^991601828744 is an apocalyptic number.

It is an amenable number.

991601828744 is a deficient number, since it is larger than the sum of its proper divisors (867651600166).

991601828744 is a wasteful number, since it uses less digits than its factorization.

991601828744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123950228599 (or 123950228595 counting only the distinct ones).

The product of its (nonzero) digits is 6967296, while the sum is 59.

The spelling of 991601828744 in words is "nine hundred ninety-one billion, six hundred one million, eight hundred twenty-eight thousand, seven hundred forty-four".