121990231989 has 24 divisors (see below), whose sum is σ = 181252259552. Its totient is φ = 79005598560.

The previous prime is 121990231969. The next prime is 121990231999. The reversal of 121990231989 is 989132099121.

It is not a de Polignac number, because 121990231989 - 2¹⁹ = 121989707701 is a prime.

It is a super-2 number, since 2×121990231989² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121990231919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 70747 + ... + 498984.

Almost surely, 2^121990231989 is an apocalyptic number.

It is an amenable number.

121990231989 is a deficient number, since it is larger than the sum of its proper divisors (59262027563).

121990231989 is a wasteful number, since it uses less digits than its factorization.

121990231989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 570417 (or 570414 counting only the distinct ones).

The product of its (nonzero) digits is 629856, while the sum is 54.

The spelling of 121990231989 in words is "one hundred twenty-one billion, nine hundred ninety million, two hundred thirty-one thousand, nine hundred eighty-nine".