1205312021534 has 16 divisors (see below), whose sum is σ = 1856920464000. Its totient is φ = 586340085024.

The previous prime is 1205312021531. The next prime is 1205312021597. The reversal of 1205312021534 is 4351202135021.

It is a junction number, because it is equal to n+sod(n) for n = 1205312021497 and 1205312021506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1205312021531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1221272 + ... + 1975380.

It is an arithmetic number, because the mean of its divisors is an integer number (116057529000).

Almost surely, 2^{1205312021534} is an apocalyptic number.

1205312021534 is a deficient number, since it is larger than the sum of its proper divisors (651608442466).

1205312021534 is a wasteful number, since it uses less digits than its factorization.

1205312021534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 775747.

The product of its (nonzero) digits is 7200, while the sum is 29.

Adding to 1205312021534 its reverse (4351202135021), we get a palindrome (5556514156555).

The spelling of 1205312021534 in words is "one trillion, two hundred five billion, three hundred twelve million, twenty-one thousand, five hundred thirty-four".