121989390 has 16 divisors (see below), whose sum is σ = 292774608. Its totient is φ = 32530496.

The previous prime is 121989377. The next prime is 121989437. The reversal of 121989390 is 93989121.

It is a super-2 number, since 2×121989390² = 29762822545144200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2033127 + ... + 2033186.

It is an arithmetic number, because the mean of its divisors is an integer number (18298413).

Almost surely, 2^121989390 is an apocalyptic number.

121989390 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

121989390 is an abundant number, since it is smaller than the sum of its proper divisors (170785218).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

121989390 is a wasteful number, since it uses less digits than its factorization.

121989390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4066323.

The product of its (nonzero) digits is 34992, while the sum is 42.

The square root of 121989390 is about 11044.8807146116. The cubic root of 121989390 is about 495.9531883284.

It can be divided in two parts, 1219 and 89390, that added together give a palindrome (90609).

The spelling of 121989390 in words is "one hundred twenty-one million, nine hundred eighty-nine thousand, three hundred ninety".