121391210 has 16 divisors (see below), whose sum is σ = 219639816. Its totient is φ = 48304128.

The previous prime is 121391197. The next prime is 121391213. The reversal of 121391210 is 12193121.

It can be written as a sum of positive squares in 4 ways, for example, as 92025649 + 29365561 = 9593^2 + 5419^2 .

It is not an unprimeable number, because it can be changed into a prime (121391213) by changing a digit.

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, 29519 + ... + 33378.

Almost surely, 2^121391210 is an apocalyptic number.

121391210 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

121391210 is a deficient number, since it is larger than the sum of its proper divisors (98248606).

121391210 is a wasteful number, since it uses less digits than its factorization.

121391210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63097.

The product of its (nonzero) digits is 108, while the sum is 20.

The square root of 121391210 is about 11017.7679227691. The cubic root of 121391210 is about 495.1412174034.

The spelling of 121391210 in words is "one hundred twenty-one million, three hundred ninety-one thousand, two hundred ten".