21222211001 has 32 divisors (see below), whose sum is σ = 23169952800. Its totient is φ = 19365068800.

The previous prime is 21222210979. The next prime is 21222211009. The reversal of 21222211001 is 10011222212.

It can be written as a sum of positive squares in 16 ways, for example, as 248220025 + 20973990976 = 15755^2 + 144824^2 .

It is a cyclic number.

It is not a de Polignac number, because 21222211001 - 2¹⁸ = 21221948857 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21222211009) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 17267255 + ... + 17268483.

It is an arithmetic number, because the mean of its divisors is an integer number (724061025).

Almost surely, 2^21222211001 is an apocalyptic number.

It is an amenable number.

21222211001 is a deficient number, since it is larger than the sum of its proper divisors (1947741799).

21222211001 is a wasteful number, since it uses less digits than its factorization.

21222211001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1549.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21222211001 its reverse (10011222212), we get a palindrome (31233433213).

The spelling of 21222211001 in words is "twenty-one billion, two hundred twenty-two million, two hundred eleven thousand, one".