21220120001 has 8 divisors (see below), whose sum is σ = 22492358280. Its totient is φ = 19950547968.

The previous prime is 21220119971. The next prime is 21220120027. The reversal of 21220120001 is 10002102212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 502835776 + 20717284225 = 22424^2 + 143935^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21220120001 - 2⁶ = 21220119937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21220020001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 650156 + ... + 682013.

It is an arithmetic number, because the mean of its divisors is an integer number (2811544785).

Almost surely, 2^21220120001 is an apocalyptic number.

It is an amenable number.

21220120001 is a deficient number, since it is larger than the sum of its proper divisors (1272238279).

21220120001 is a wasteful number, since it uses less digits than its factorization.

21220120001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1333123.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21220120001 its reverse (10002102212), we get a palindrome (31222222213).

The spelling of 21220120001 in words is "twenty-one billion, two hundred twenty million, one hundred twenty thousand, one".