189056505721 has 4 divisors (see below), whose sum is σ = 189627673744. Its totient is φ = 188485337700.

The previous prime is 189056505709. The next prime is 189056505749. The reversal of 189056505721 is 127505650981.

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, and also an emirpimes, since its reverse is a distinct semiprime: 127505650981 = 227 ⋅561698903.

It is a cyclic number.

It is not a de Polignac number, because 189056505721 - 2¹¹ = 189056503673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (189056505751) 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, 285583515 + ... + 285584176.

It is an arithmetic number, because the mean of its divisors is an integer number (47406918436).

Almost surely, 2^189056505721 is an apocalyptic number.

It is an amenable number.

189056505721 is a deficient number, since it is larger than the sum of its proper divisors (571168023).

189056505721 is an equidigital number, since it uses as much as digits as its factorization.

189056505721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 571168022.

The product of its (nonzero) digits is 756000, while the sum is 49.

The spelling of 189056505721 in words is "one hundred eighty-nine billion, fifty-six million, five hundred five thousand, seven hundred twenty-one".