19991532005 has 12 divisors (see below), whose sum is σ = 25318917612. Its totient is φ = 15151475520.

The previous prime is 19991531971. The next prime is 19991532031. The reversal of 19991532005 is 50023519991.

It can be written as a sum of positive squares in 2 ways, for example, as 5177234209 + 14814297796 = 71953^2 + 121714^2 .

It is a de Polignac number, because none of the positive numbers 2^k-19991532005 is a prime.

It is a super-2 number, since 2×19991532005² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5536016 + ... + 5539625.

It is an arithmetic number, because the mean of its divisors is an integer number (2109909801).

Almost surely, 2^19991532005 is an apocalyptic number.

It is an amenable number.

19991532005 is a deficient number, since it is larger than the sum of its proper divisors (5327385607).

19991532005 is a wasteful number, since it uses less digits than its factorization.

19991532005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11075684 (or 11075665 counting only the distinct ones).

The product of its (nonzero) digits is 109350, while the sum is 44.

The spelling of 19991532005 in words is "nineteen billion, nine hundred ninety-one million, five hundred thirty-two thousand, five".