19995770387 has 4 divisors (see below), whose sum is σ = 19996213656. Its totient is φ = 19995327120.

The previous prime is 19995770369. The next prime is 19995770401. The reversal of 19995770387 is 78307759991.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 19995770387 - 2⁶ = 19995770323 is a prime.

It is a super-2 number, since 2×19995770387² (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 (19995770317) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 145178 + ... + 247119.

It is an arithmetic number, because the mean of its divisors is an integer number (4999053414).

Almost surely, 2^19995770387 is an apocalyptic number.

19995770387 is a deficient number, since it is larger than the sum of its proper divisors (443269).

19995770387 is an equidigital number, since it uses as much as digits as its factorization.

19995770387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 443268.

The product of its (nonzero) digits is 30005640, while the sum is 65.

The spelling of 19995770387 in words is "nineteen billion, nine hundred ninety-five million, seven hundred seventy thousand, three hundred eighty-seven".