1221250043534 has 4 divisors (see below), whose sum is σ = 1831875065304. Its totient is φ = 610625021766.

The previous prime is 1221250043491. The next prime is 1221250043549. The reversal of 1221250043534 is 4353400521221.

It is a semiprime because it is the product of two primes.

It is a self number, because there is not a number n which added to its sum of digits gives 1221250043534.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 305312510882 + ... + 305312510885.

It is an arithmetic number, because the mean of its divisors is an integer number (457968766326).

Almost surely, 2^{1221250043534} is an apocalyptic number.

1221250043534 is a deficient number, since it is larger than the sum of its proper divisors (610625021770).

1221250043534 is an equidigital number, since it uses as much as digits as its factorization.

1221250043534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 610625021769.

The product of its (nonzero) digits is 28800, while the sum is 32.

Adding to 1221250043534 its reverse (4353400521221), we get a palindrome (5574650564755).

The spelling of 1221250043534 in words is "one trillion, two hundred twenty-one billion, two hundred fifty million, forty-three thousand, five hundred thirty-four".