20189387747 has 4 divisors (see below), whose sum is σ = 20225248680. Its totient is φ = 20153526816.

The previous prime is 20189387677. The next prime is 20189387761. The reversal of 20189387747 is 74778398102.

It is a happy number.

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 20189387747 - 2¹⁸ = 20189125603 is a prime.

It is a super-2 number, since 2×20189387747² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20189387692 and 20189387701.

It is not an unprimeable number, because it can be changed into a prime (20189387797) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17929622 + ... + 17930747.

It is an arithmetic number, because the mean of its divisors is an integer number (5056312170).

Almost surely, 2^20189387747 is an apocalyptic number.

20189387747 is a deficient number, since it is larger than the sum of its proper divisors (35860933).

20189387747 is an equidigital number, since it uses as much as digits as its factorization.

20189387747 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35860932.

The product of its (nonzero) digits is 4741632, while the sum is 56.

The spelling of 20189387747 in words is "twenty billion, one hundred eighty-nine million, three hundred eighty-seven thousand, seven hundred forty-seven".