1081855821971 has 16 divisors (see below), whose sum is σ = 1148411382624. Its totient is φ = 1015626852864.

The previous prime is 1081855821929. The next prime is 1081855821979. The reversal of 1081855821971 is 1791285581801.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1081855821971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1081855821979) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14303465 + ... + 14378901.

It is an arithmetic number, because the mean of its divisors is an integer number (71775711414).

Almost surely, 2^{1081855821971} is an apocalyptic number.

1081855821971 is a deficient number, since it is larger than the sum of its proper divisors (66555560653).

1081855821971 is a wasteful number, since it uses less digits than its factorization.

1081855821971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77590.

The product of its (nonzero) digits is 1612800, while the sum is 56.

The spelling of 1081855821971 in words is "one trillion, eighty-one billion, eight hundred fifty-five million, eight hundred twenty-one thousand, nine hundred seventy-one".