19131440840 has 16 divisors (see below), whose sum is σ = 43045741980. Its totient is φ = 7652576320.

The previous prime is 19131440837. The next prime is 19131440863. The reversal of 19131440840 is 4804413191.

It can be written as a sum of positive squares in 2 ways, for example, as 19061115844 + 70324996 = 138062^2 + 8386^2 .

It is a super-2 number, since 2×19131440840² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 19131440840.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 239142971 + ... + 239143050.

Almost surely, 2^19131440840 is an apocalyptic number.

19131440840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19131440840 is an abundant number, since it is smaller than the sum of its proper divisors (23914301140).

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

19131440840 is a wasteful number, since it uses less digits than its factorization.

19131440840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 478286032 (or 478286028 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 35.

The spelling of 19131440840 in words is "nineteen billion, one hundred thirty-one million, four hundred forty thousand, eight hundred forty".