21401222001 has 4 divisors (see below), whose sum is σ = 28534962672. Its totient is φ = 14267481332.

The previous prime is 21401221951. The next prime is 21401222039. The reversal of 21401222001 is 10022210412.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21401222001 - 2⁶ = 21401221937 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21401922001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3566870331 + ... + 3566870336.

It is an arithmetic number, because the mean of its divisors is an integer number (7133740668).

Almost surely, 2^21401222001 is an apocalyptic number.

It is an amenable number.

21401222001 is a deficient number, since it is larger than the sum of its proper divisors (7133740671).

21401222001 is an equidigital number, since it uses as much as digits as its factorization.

21401222001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7133740670.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21401222001 its reverse (10022210412), we get a palindrome (31423432413).

The spelling of 21401222001 in words is "twenty-one billion, four hundred one million, two hundred twenty-two thousand, one".