1181478444021 has 6 divisors (see below), whose sum is σ = 1706579974710. Its totient is φ = 787652296008.

The previous prime is 1181478443993. The next prime is 1181478444049. The reversal of 1181478444021 is 1204448741811.

1181478444021 is a `hidden beast` number, since 1 + 1 + 81 + 478 + 44 + 40 + 21 = 666.

It is an interprime number because it is at equal distance from previous prime (1181478443993) and next prime (1181478444049).

It can be written as a sum of positive squares in only one way, i.e., 1169888844996 + 11589599025 = 1081614^2 + 107655^2 .

It is not a de Polignac number, because 1181478444021 - 2¹⁴ = 1181478427637 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1181478444721) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 65637691326 + ... + 65637691343.

It is an arithmetic number, because the mean of its divisors is an integer number (284429995785).

Almost surely, 2^{1181478444021} is an apocalyptic number.

It is an amenable number.

1181478444021 is a deficient number, since it is larger than the sum of its proper divisors (525101530689).

1181478444021 is a wasteful number, since it uses less digits than its factorization.

1181478444021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131275382675 (or 131275382672 counting only the distinct ones).

The product of its (nonzero) digits is 229376, while the sum is 45.

The spelling of 1181478444021 in words is "one trillion, one hundred eighty-one billion, four hundred seventy-eight million, four hundred forty-four thousand, twenty-one".