121905820 has 12 divisors (see below), whose sum is σ = 256002264. Its totient is φ = 48762320.

The previous prime is 121905803. The next prime is 121905829. The reversal of 121905820 is 28509121.

It is a super-2 number, since 2×121905820² = 29722057899744800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121905829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3047626 + ... + 3047665.

It is an arithmetic number, because the mean of its divisors is an integer number (21333522).

Almost surely, 2^121905820 is an apocalyptic number.

121905820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121905820 is an abundant number, since it is smaller than the sum of its proper divisors (134096444).

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

121905820 is a wasteful number, since it uses less digits than its factorization.

121905820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6095300 (or 6095298 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 121905820 is about 11041.0968658010. The cubic root of 121905820 is about 495.8399099631.

The spelling of 121905820 in words is "one hundred twenty-one million, nine hundred five thousand, eight hundred twenty".