188961030721 has 4 divisors (see below), whose sum is σ = 188962585344. Its totient is φ = 188959476100.

The previous prime is 188961030691. The next prime is 188961030737. The reversal of 188961030721 is 127030169881.

It is a happy number.

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: 127030169881 = 94573 ⋅1343197.

It is a cyclic number.

It is not a de Polignac number, because 188961030721 - 2³¹ = 186813547073 is a prime.

It is a super-2 number, since 2×188961030721² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (188961030781) 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, 577945 + ... + 843766.

It is an arithmetic number, because the mean of its divisors is an integer number (47240646336).

Almost surely, 2^188961030721 is an apocalyptic number.

It is an amenable number.

188961030721 is a deficient number, since it is larger than the sum of its proper divisors (1554623).

188961030721 is a wasteful number, since it uses less digits than its factorization.

188961030721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1554622.

The product of its (nonzero) digits is 145152, while the sum is 46.

The spelling of 188961030721 in words is "one hundred eighty-eight billion, nine hundred sixty-one million, thirty thousand, seven hundred twenty-one".