1221352531221 has 8 divisors (see below), whose sum is σ = 1631595705984. Its totient is φ = 812672188640.

The previous prime is 1221352531187. The next prime is 1221352531229.

1221352531221 is nontrivially palindromic in base 10.

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 1221352531221 - 2¹³ = 1221352523029 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221352531229) 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, 390706221 + ... + 390709346.

It is an arithmetic number, because the mean of its divisors is an integer number (203949463248).

Almost surely, 2^{1221352531221} is an apocalyptic number.

It is an amenable number.

1221352531221 is a deficient number, since it is larger than the sum of its proper divisors (410243174763).

1221352531221 is an equidigital number, since it uses as much as digits as its factorization.

1221352531221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 781416091.

The product of its digits is 7200, while the sum is 30.

The spelling of 1221352531221 in words is "one trillion, two hundred twenty-one billion, three hundred fifty-two million, five hundred thirty-one thousand, two hundred twenty-one".