189990501981 has 16 divisors (see below), whose sum is σ = 296242113024. Its totient is φ = 106041209904.

The previous prime is 189990501971. The next prime is 189990502049. The reversal of 189990501981 is 189105099981.

It is not a de Polignac number, because 189990501981 - 2¹⁷ = 189990370909 is a prime.

It is a super-2 number, since 2×189990501981² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (189990501971) 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, 105198711 + ... + 105200516.

It is an arithmetic number, because the mean of its divisors is an integer number (18515132064).

Almost surely, 2^189990501981 is an apocalyptic number.

It is an amenable number.

189990501981 is a deficient number, since it is larger than the sum of its proper divisors (106251611043).

189990501981 is a wasteful number, since it uses less digits than its factorization.

189990501981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210399280.

The product of its (nonzero) digits is 2099520, while the sum is 60.

The spelling of 189990501981 in words is "one hundred eighty-nine billion, nine hundred ninety million, five hundred one thousand, nine hundred eighty-one".