189856743551 has 4 divisors (see below), whose sum is σ = 189904057992. Its totient is φ = 189809429112.

The previous prime is 189856743547. The next prime is 189856743581. The reversal of 189856743551 is 155347658981.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 155347658981 = 8803 ⋅17647127.

It is a cyclic number.

It is not a de Polignac number, because 189856743551 - 2² = 189856743547 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (189856743581) 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, 23651201 + ... + 23659226.

It is an arithmetic number, because the mean of its divisors is an integer number (47476014498).

Almost surely, 2^189856743551 is an apocalyptic number.

189856743551 is a deficient number, since it is larger than the sum of its proper divisors (47314441).

189856743551 is an equidigital number, since it uses as much as digits as its factorization.

189856743551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47314440.

The product of its digits is 36288000, while the sum is 62.

The spelling of 189856743551 in words is "one hundred eighty-nine billion, eight hundred fifty-six million, seven hundred forty-three thousand, five hundred fifty-one".