15515252321213 has 4 divisors (see below), whose sum is σ = 15516418105980. Its totient is φ = 15514086536448.

The previous prime is 15515252321183. The next prime is 15515252321273. The reversal of 15515252321213 is 31212325251551.

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

It can be written as a sum of positive squares in 2 ways, for example, as 7470529833529 + 8044722487684 = 2733227^2 + 2836322^2 .

It is a cyclic number.

It is not a de Polignac number, because 15515252321213 - 2¹⁰ = 15515252320189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15515252321273) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 582872420 + ... + 582899037.

It is an arithmetic number, because the mean of its divisors is an integer number (3879104526495).

Almost surely, 2^{15515252321213} is an apocalyptic number.

It is an amenable number.

15515252321213 is a deficient number, since it is larger than the sum of its proper divisors (1165784767).

15515252321213 is a wasteful number, since it uses less digits than its factorization.

15515252321213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1165784766.

The product of its digits is 90000, while the sum is 38.

Adding to 15515252321213 its reverse (31212325251551), we get a palindrome (46727577572764).

The spelling of 15515252321213 in words is "fifteen trillion, five hundred fifteen billion, two hundred fifty-two million, three hundred twenty-one thousand, two hundred thirteen".