1221001521006 has 32 divisors (see below), whose sum is σ = 2485547608320. Its totient is φ = 399755049984.

The previous prime is 1221001521001. The next prime is 1221001521007. The reversal of 1221001521006 is 6001251001221.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221001521001) 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, 1087570 + ... + 1903893.

It is an arithmetic number, because the mean of its divisors is an integer number (77673362760).

Almost surely, 2^{1221001521006} is an apocalyptic number.

1221001521006 is an abundant number, since it is smaller than the sum of its proper divisors (1264546087314).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221001521006 is a wasteful number, since it uses less digits than its factorization.

1221001521006 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2992680.

The product of its (nonzero) digits is 240, while the sum is 21.

Adding to 1221001521006 its reverse (6001251001221), we get a palindrome (7222252522227).

The spelling of 1221001521006 in words is "one trillion, two hundred twenty-one billion, one million, five hundred twenty-one thousand, six".