221221021001001 has 64 divisors (see below), whose sum is σ = 366982803726336. Its totient is φ = 115645837363200.

The previous prime is 221221021000949. The next prime is 221221021001011. The reversal of 221221021001001 is 100100120122122.

It is not a de Polignac number, because 221221021001001 - 2⁶ = 221221021000937 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221221021001011) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 23918655 + ... + 31851908.

It is an arithmetic number, because the mean of its divisors is an integer number (5734106308224).

Almost surely, 2^{221221021001001} is an apocalyptic number.

221221021001001 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

221221021001001 is a deficient number, since it is larger than the sum of its proper divisors (145761782725335).

221221021001001 is a wasteful number, since it uses less digits than its factorization.

221221021001001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55770902.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 221221021001001 its reverse (100100120122122), we get a palindrome (321321141123123).

The spelling of 221221021001001 in words is "two hundred twenty-one trillion, two hundred twenty-one billion, twenty-one million, one thousand, one".