189212981 has 4 divisors (see below), whose sum is σ = 190164000. Its totient is φ = 188261964.

The previous prime is 189212971. The next prime is 189212987.

It is a happy number.

189212981 is nontrivially palindromic in base 10.

189212981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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.

It is a cyclic number.

It is not a de Polignac number, because 189212981 - 2²² = 185018677 is a prime.

It is a super-2 number, since 2×189212981² = 71603104357812722, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (189212987) 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, 475211 + ... + 475608.

It is an arithmetic number, because the mean of its divisors is an integer number (47541000).

Almost surely, 2^189212981 is an apocalyptic number.

It is an amenable number.

189212981 is a deficient number, since it is larger than the sum of its proper divisors (951019).

189212981 is an equidigital number, since it uses as much as digits as its factorization.

189212981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 951018.

The product of its digits is 20736, while the sum is 41.

The square root of 189212981 is about 13755.4709479538. The cubic root of 189212981 is about 574.0948389875.

The spelling of 189212981 in words is "one hundred eighty-nine million, two hundred twelve thousand, nine hundred eighty-one".