21001121229 has 16 divisors (see below), whose sum is σ = 31292138304. Its totient is φ = 12417513600.

The previous prime is 21001121189. The next prime is 21001121279. The reversal of 21001121229 is 92212110012.

It is not a de Polignac number, because 21001121229 - 2¹² = 21001117133 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001121279) 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, 7759594 + ... + 7762299.

It is an arithmetic number, because the mean of its divisors is an integer number (1955758644).

Almost surely, 2^21001121229 is an apocalyptic number.

It is an amenable number.

21001121229 is a deficient number, since it is larger than the sum of its proper divisors (10291017075).

21001121229 is a wasteful number, since it uses less digits than its factorization.

21001121229 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15521948.

The product of its (nonzero) digits is 144, while the sum is 21.

The spelling of 21001121229 in words is "twenty-one billion, one million, one hundred twenty-one thousand, two hundred twenty-nine".