121864021 has 4 divisors (see below), whose sum is σ = 124698112. Its totient is φ = 119029932.

The previous prime is 121863991. The next prime is 121864033. The reversal of 121864021 is 120468121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 121864021 - 2¹⁹ = 121339733 is a prime.

It is a super-2 number, since 2×121864021² = 29701679228576882, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121864121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1416981 + ... + 1417066.

It is an arithmetic number, because the mean of its divisors is an integer number (31174528).

Almost surely, 2^121864021 is an apocalyptic number.

It is an amenable number.

121864021 is a deficient number, since it is larger than the sum of its proper divisors (2834091).

121864021 is an equidigital number, since it uses as much as digits as its factorization.

121864021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2834090.

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 121864021 is about 11039.2038209284. The cubic root of 121864021 is about 495.7832323802.

The spelling of 121864021 in words is "one hundred twenty-one million, eight hundred sixty-four thousand, twenty-one".