215131121545 has 16 divisors (see below), whose sum is σ = 266631389712. Its totient is φ = 166544501760.

The previous prime is 215131121537. The next prime is 215131121561. The reversal of 215131121545 is 545121131512.

It can be written as a sum of positive squares in 8 ways, for example, as 1531861321 + 213599260224 = 39139^2 + 462168^2 .

It is not a de Polignac number, because 215131121545 - 2³ = 215131121537 is a prime.

It is a Duffinian 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, 5541036 + ... + 5579725.

It is an arithmetic number, because the mean of its divisors is an integer number (16664461857).

Almost surely, 2^215131121545 is an apocalyptic number.

It is an amenable number.

215131121545 is a deficient number, since it is larger than the sum of its proper divisors (51500268167).

215131121545 is a wasteful number, since it uses less digits than its factorization.

215131121545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11120892.

The product of its digits is 6000, while the sum is 31.

The spelling of 215131121545 in words is "two hundred fifteen billion, one hundred thirty-one million, one hundred twenty-one thousand, five hundred forty-five".