1021155044555 has 16 divisors (see below), whose sum is σ = 1290776601600. Its totient is φ = 773390106720.

The previous prime is 1021155044531. The next prime is 1021155044597. The reversal of 1021155044555 is 5554405511201.

It is a de Polignac number, because none of the positive numbers 2^k-1021155044555 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3598181 + ... + 3871590.

It is an arithmetic number, because the mean of its divisors is an integer number (80673537600).

Almost surely, 2^{1021155044555} is an apocalyptic number.

1021155044555 is a deficient number, since it is larger than the sum of its proper divisors (269621557045).

1021155044555 is a wasteful number, since it uses less digits than its factorization.

1021155044555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7471234.

The product of its (nonzero) digits is 100000, while the sum is 38.

The spelling of 1021155044555 in words is "one trillion, twenty-one billion, one hundred fifty-five million, forty-four thousand, five hundred fifty-five".