21031332121 has 16 divisors (see below), whose sum is σ = 22287418560. Its totient is φ = 19811695680.

The previous prime is 21031332103. The next prime is 21031332131. The reversal of 21031332121 is 12123313012.

It is not a de Polignac number, because 21031332121 - 2¹⁵ = 21031299353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21031332131) 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, 1164466 + ... + 1182388.

It is an arithmetic number, because the mean of its divisors is an integer number (1392963660).

Almost surely, 2^21031332121 is an apocalyptic number.

It is an amenable number.

21031332121 is a deficient number, since it is larger than the sum of its proper divisors (1256086439).

21031332121 is a wasteful number, since it uses less digits than its factorization.

21031332121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18936.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 21031332121 its reverse (12123313012), we get a palindrome (33154645133).

The spelling of 21031332121 in words is "twenty-one billion, thirty-one million, three hundred thirty-two thousand, one hundred twenty-one".