9121212121021 has 64 divisors (see below), whose sum is σ = 12302188609536. Its totient is φ = 6531032851200.

The previous prime is 9121212120991. The next prime is 9121212121039. The reversal of 9121212121021 is 1201212121219.

It is not a de Polignac number, because 9121212121021 - 2⁷ = 9121212120893 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9121212121121) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 199867876 + ... + 199913506.

It is an arithmetic number, because the mean of its divisors is an integer number (192221697024).

Almost surely, 2^{9121212121021} is an apocalyptic number.

9121212121021 is a gapful number since it is divisible by the number (91) formed by its first and last digit.

It is an amenable number.

9121212121021 is a deficient number, since it is larger than the sum of its proper divisors (3180976488515).

9121212121021 is a wasteful number, since it uses less digits than its factorization.

9121212121021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46562.

The product of its (nonzero) digits is 288, while the sum is 25.

The spelling of 9121212121021 in words is "nine trillion, one hundred twenty-one billion, two hundred twelve million, one hundred twenty-one thousand, twenty-one".