19512940081 has 4 divisors (see below), whose sum is σ = 19513267200. Its totient is φ = 19512612964.

The previous prime is 19512940067. The next prime is 19512940103. The reversal of 19512940081 is 18004921591.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 19512940081 - 2²¹ = 19510842929 is a prime.

It is a super-2 number, since 2×19512940081² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19512946081) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 45841 + ... + 202798.

It is an arithmetic number, because the mean of its divisors is an integer number (4878316800).

Almost surely, 2^19512940081 is an apocalyptic number.

It is an amenable number.

19512940081 is a deficient number, since it is larger than the sum of its proper divisors (327119).

19512940081 is an equidigital number, since it uses as much as digits as its factorization.

19512940081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 327118.

The product of its (nonzero) digits is 25920, while the sum is 40.

The spelling of 19512940081 in words is "nineteen billion, five hundred twelve million, nine hundred forty thousand, eighty-one".