21312435223045 has 16 divisors (see below), whose sum is σ = 26906773865328. Its totient is φ = 16184525621760.

The previous prime is 21312435223033. The next prime is 21312435223063. The reversal of 21312435223045 is 54032253421312.

It can be written as a sum of positive squares in 8 ways, for example, as 2175371307396 + 19137063915649 = 1474914^2 + 4374593^2 .

It is a de Polignac number, because none of the positive numbers 2^k-21312435223045 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21312435222995 and 21312435223013.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 1404899154 + ... + 1404914323.

It is an arithmetic number, because the mean of its divisors is an integer number (1681673366583).

Almost surely, 2^{21312435223045} is an apocalyptic number.

It is an amenable number.

21312435223045 is a deficient number, since it is larger than the sum of its proper divisors (5594338642283).

21312435223045 is a wasteful number, since it uses less digits than its factorization.

21312435223045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2809813560.

The product of its (nonzero) digits is 172800, while the sum is 37.

Adding to 21312435223045 its reverse (54032253421312), we get a palindrome (75344688644357).

The spelling of 21312435223045 in words is "twenty-one trillion, three hundred twelve billion, four hundred thirty-five million, two hundred twenty-three thousand, forty-five".