1221155310523 has 8 divisors (see below), whose sum is σ = 1222249946400. Its totient is φ = 1220060994240.

The previous prime is 1221155310409. The next prime is 1221155310601. The reversal of 1221155310523 is 3250135511221.

It is a happy number.

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 1221155310523 - 2¹⁷ = 1221155179451 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221155314523) 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, 7921743 + ... + 8074423.

It is an arithmetic number, because the mean of its divisors is an integer number (152781243300).

Almost surely, 2^{1221155310523} is an apocalyptic number.

1221155310523 is a deficient number, since it is larger than the sum of its proper divisors (1094635877).

1221155310523 is a wasteful number, since it uses less digits than its factorization.

1221155310523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159797.

The product of its (nonzero) digits is 9000, while the sum is 31.

The spelling of 1221155310523 in words is "one trillion, two hundred twenty-one billion, one hundred fifty-five million, three hundred ten thousand, five hundred twenty-three".