121989139 has 8 divisors (see below), whose sum is σ = 128947280. Its totient is φ = 115084800.

The previous prime is 121989121. The next prime is 121989143. The reversal of 121989139 is 931989121.

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

It is a cyclic number.

It is not a de Polignac number, because 121989139 - 2⁵ = 121989107 is a prime.

It is a super-2 number, since 2×121989139² = 29762700067922642, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121989095 and 121989104.

It is not an unprimeable number, because it can be changed into a prime (121989149) 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, 8742 + ... + 17899.

It is an arithmetic number, because the mean of its divisors is an integer number (16118410).

Almost surely, 2^121989139 is an apocalyptic number.

121989139 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

121989139 is a deficient number, since it is larger than the sum of its proper divisors (6958141).

121989139 is a wasteful number, since it uses less digits than its factorization.

121989139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26901.

The product of its digits is 34992, while the sum is 43.

The square root of 121989139 is about 11044.8693518756. The cubic root of 121989139 is about 495.9528481777.

The spelling of 121989139 in words is "one hundred twenty-one million, nine hundred eighty-nine thousand, one hundred thirty-nine".