121100021 has 12 divisors (see below), whose sum is σ = 142977888. Its totient is φ = 102247992.

The previous prime is 121100017. The next prime is 121100029. The reversal of 121100021 is 120001121.

It is not a de Polignac number, because 121100021 - 2² = 121100017 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 121099981 and 121100008.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121100029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15161 + ... + 21726.

It is an arithmetic number, because the mean of its divisors is an integer number (11914824).

Almost surely, 2^121100021 is an apocalyptic number.

It is an amenable number.

121100021 is a deficient number, since it is larger than the sum of its proper divisors (21877867).

121100021 is an equidigital number, since it uses as much as digits as its factorization.

121100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36968 (or 36961 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 8.

The square root of 121100021 is about 11004.5454699410. The cubic root of 121100021 is about 494.7449912565.

Adding to 121100021 its reverse (120001121), we get a palindrome (241101142).

The spelling of 121100021 in words is "one hundred twenty-one million, one hundred thousand, twenty-one".