991923436 has 24 divisors (see below), whose sum is σ = 1991404800. Its totient is φ = 423490512.

The previous prime is 991923433. The next prime is 991923451. The reversal of 991923436 is 634329199.

It is not an unprimeable number, because it can be changed into a prime (991923431) 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, 59986 + ... + 74713.

It is an arithmetic number, because the mean of its divisors is an integer number (82975200).

Almost surely, 2^991923436 is an apocalyptic number.

It is an amenable number.

991923436 is an abundant number, since it is smaller than the sum of its proper divisors (999481364).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

991923436 is a wasteful number, since it uses less digits than its factorization.

991923436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134973 (or 134971 counting only the distinct ones).

The product of its digits is 314928, while the sum is 46.

The square root of 991923436 is about 31494.8160178782. The cubic root of 991923436 is about 997.3005314265.

The spelling of 991923436 in words is "nine hundred ninety-one million, nine hundred twenty-three thousand, four hundred thirty-six".