121001000021 has 16 divisors (see below), whose sum is σ = 132778251648. Its totient is φ = 109355097600.

The previous prime is 121001000017. The next prime is 121001000041. The reversal of 121001000021 is 120000100121.

It is a cyclic number.

It is not a de Polignac number, because 121001000021 - 2² = 121001000017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121000999972 and 121001000008.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121001000041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1293200 + ... + 1383606.

It is an arithmetic number, because the mean of its divisors is an integer number (8298640728).

Almost surely, 2^121001000021 is an apocalyptic number.

121001000021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121001000021 is a deficient number, since it is larger than the sum of its proper divisors (11777251627).

121001000021 is a wasteful number, since it uses less digits than its factorization.

121001000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91132.

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

Adding to 121001000021 its reverse (120000100121), we get a palindrome (241001100142).

The spelling of 121001000021 in words is "one hundred twenty-one billion, one million, twenty-one", and thus it is an aban number.