21220010001 has 12 divisors (see below), whose sum is σ = 30665536720. Its totient is φ = 14140022040.

The previous prime is 21220009973. The next prime is 21220010023. The reversal of 21220010001 is 10001002212.

It is not a de Polignac number, because 21220010001 - 2¹³ = 21220001809 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21220010081) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 534031 + ... + 572388.

Almost surely, 2^21220010001 is an apocalyptic number.

It is an amenable number.

21220010001 is a deficient number, since it is larger than the sum of its proper divisors (9445526719).

21220010001 is a wasteful number, since it uses less digits than its factorization.

21220010001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1108556 (or 1108553 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 21220010001 its reverse (10001002212), we get a palindrome (31221012213).

It can be divided in two parts, 21 and 220010001, that added together give a palindrome (220010022).

The spelling of 21220010001 in words is "twenty-one billion, two hundred twenty million, ten thousand, one".