19910231544 has 48 divisors (see below), whose sum is σ = 57902207400. Its totient is φ = 5688637248.

The previous prime is 19910231533. The next prime is 19910231599. The reversal of 19910231544 is 44513201991.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8464059 + ... + 8466410.

Almost surely, 2^19910231544 is an apocalyptic number.

19910231544 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

19910231544 is an abundant number, since it is smaller than the sum of its proper divisors (37991975856).

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

19910231544 is a wasteful number, since it uses less digits than its factorization.

19910231544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16930492 (or 16930481 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 39.

The spelling of 19910231544 in words is "nineteen billion, nine hundred ten million, two hundred thirty-one thousand, five hundred forty-four".