256106215515 has 8 divisors (see below), whose sum is σ = 409769944848. Its totient is φ = 136589981600.

The previous prime is 256106215507. The next prime is 256106215529. The reversal of 256106215515 is 515512601652.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 256106215515 - 2³ = 256106215507 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8536873836 + ... + 8536873865.

It is an arithmetic number, because the mean of its divisors is an integer number (51221243106).

Almost surely, 2^256106215515 is an apocalyptic number.

256106215515 is a deficient number, since it is larger than the sum of its proper divisors (153663729333).

256106215515 is a wasteful number, since it uses less digits than its factorization.

256106215515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17073747709.

The product of its (nonzero) digits is 90000, while the sum is 39.

The spelling of 256106215515 in words is "two hundred fifty-six billion, one hundred six million, two hundred fifteen thousand, five hundred fifteen".