120921921 has 6 divisors (see below), whose sum is σ = 174665010. Its totient is φ = 80614608.

The previous prime is 120921893. The next prime is 120921923. The reversal of 120921921 is 129129021.

It can be written as a sum of positive squares in only one way, i.e., 115347600 + 5574321 = 10740^2 + 2361^2 .

It is not a de Polignac number, because 120921921 - 2¹⁰ = 120920897 is a prime.

It is a super-2 number, since 2×120921921² = 29244221956660482, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (120921923) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6717876 + ... + 6717893.

It is an arithmetic number, because the mean of its divisors is an integer number (29110835).

Almost surely, 2^120921921 is an apocalyptic number.

It is an amenable number.

120921921 is a deficient number, since it is larger than the sum of its proper divisors (53743089).

120921921 is a wasteful number, since it uses less digits than its factorization.

120921921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13435775 (or 13435772 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The square root of 120921921 is about 10996.4503818278. The cubic root of 120921921 is about 494.5023342264.

The spelling of 120921921 in words is "one hundred twenty million, nine hundred twenty-one thousand, nine hundred twenty-one".