19712536440 has 64 divisors (see below), whose sum is σ = 60512918400. Its totient is φ = 5134426752.

The previous prime is 19712536409. The next prime is 19712536457. The reversal of 19712536440 is 4463521791.

It is a junction number, because it is equal to n+sod(n) for n = 19712536392 and 19712536401.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1904970 + ... + 1915289.

It is an arithmetic number, because the mean of its divisors is an integer number (945514350).

Almost surely, 2^19712536440 is an apocalyptic number.

19712536440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19712536440 is an abundant number, since it is smaller than the sum of its proper divisors (40800381960).

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

19712536440 is a wasteful number, since it uses less digits than its factorization.

19712536440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3820316 (or 3820312 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 42.

The spelling of 19712536440 in words is "nineteen billion, seven hundred twelve million, five hundred thirty-six thousand, four hundred forty".