22001000021 has 16 divisors (see below), whose sum is σ = 29539805568. Its totient is φ = 15824894400.

The previous prime is 22001000003. The next prime is 22001000023. The reversal of 22001000021 is 12000010022.

It is not a de Polignac number, because 22001000021 - 2⁶ = 22000999957 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 22000999972 and 22001000008.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22001000023) 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, 10988510 + ... + 10990511.

It is an arithmetic number, because the mean of its divisors is an integer number (1846237848).

Almost surely, 2^22001000021 is an apocalyptic number.

It is an amenable number.

22001000021 is a deficient number, since it is larger than the sum of its proper divisors (7538805547).

22001000021 is a wasteful number, since it uses less digits than its factorization.

22001000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21979052.

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

Adding to 22001000021 its reverse (12000010022), we get a palindrome (34001010043).

The spelling of 22001000021 in words is "twenty-two billion, one million, twenty-one", and thus it is an aban number and an uban number.