189771891 has 8 divisors (see below), whose sum is σ = 253755600. Its totient is φ = 126151392.

The previous prime is 189771877. The next prime is 189771893. The reversal of 189771891 is 198177981.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 189771891 - 2¹¹ = 189769843 is a prime.

It is a super-2 number, since 2×189771891² = 72026741227431762, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (189771893) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 89580 + ... + 91673.

It is an arithmetic number, because the mean of its divisors is an integer number (31719450).

Almost surely, 2^189771891 is an apocalyptic number.

189771891 is a deficient number, since it is larger than the sum of its proper divisors (63983709).

189771891 is a wasteful number, since it uses less digits than its factorization.

189771891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 181605.

The product of its digits is 254016, while the sum is 51.

The square root of 189771891 is about 13775.7718839998. The cubic root of 189771891 is about 574.6595499445.

The spelling of 189771891 in words is "one hundred eighty-nine million, seven hundred seventy-one thousand, eight hundred ninety-one".