189969981 has 16 divisors (see below), whose sum is σ = 262526400. Its totient is φ = 122046848.

The previous prime is 189969979. The next prime is 189970003.

It is a happy number.

189969981 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 189969981 - 2¹ = 189969979 is a prime.

It is a super-2 number, since 2×189969981² = 72177187362280722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (189969971) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 51910 + ... + 55448.

It is an arithmetic number, because the mean of its divisors is an integer number (16407900).

Almost surely, 2^189969981 is an apocalyptic number.

It is an amenable number.

189969981 is a deficient number, since it is larger than the sum of its proper divisors (72556419).

189969981 is a wasteful number, since it uses less digits than its factorization.

189969981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4188.

The product of its digits is 2519424, while the sum is 60.

The square root of 189969981 is about 13782.9598054990. The cubic root of 189969981 is about 574.8594297838.

The spelling of 189969981 in words is "one hundred eighty-nine million, nine hundred sixty-nine thousand, nine hundred eighty-one".