1001220100021 has 4 divisors (see below), whose sum is σ = 1001551303872. Its totient is φ = 1000888896172.

The previous prime is 1001220099967. The next prime is 1001220100057. The reversal of 1001220100021 is 1200010221001.

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 1001220100021 - 2¹³ = 1001220091829 is a prime.

It is a super-2 number, since 2×1001220100021² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1001220099980 and 1001220100007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1001220130021) 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, 165597391 + ... + 165603436.

It is an arithmetic number, because the mean of its divisors is an integer number (250387825968).

Almost surely, 2^{1001220100021} is an apocalyptic number.

It is an amenable number.

1001220100021 is a deficient number, since it is larger than the sum of its proper divisors (331203851).

1001220100021 is an equidigital number, since it uses as much as digits as its factorization.

1001220100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331203850.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 1001220100021 its reverse (1200010221001), we get a palindrome (2201230321022).

It can be divided in two parts, 1001 and 220100021, that added together give a palindrome (220101022).

The spelling of 1001220100021 in words is "one trillion, one billion, two hundred twenty million, one hundred thousand, twenty-one".