1081621801667 has 4 divisors (see below), whose sum is σ = 1179951056376. Its totient is φ = 983292546960.

The previous prime is 1081621801643. The next prime is 1081621801699. The reversal of 1081621801667 is 7661081261801.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1081621801667 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1081621801607) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49164627338 + ... + 49164627359.

It is an arithmetic number, because the mean of its divisors is an integer number (294987764094).

Almost surely, 2^{1081621801667} is an apocalyptic number.

1081621801667 is a deficient number, since it is larger than the sum of its proper divisors (98329254709).

1081621801667 is an equidigital number, since it uses as much as digits as its factorization.

1081621801667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98329254708.

The product of its (nonzero) digits is 193536, while the sum is 47.

The spelling of 1081621801667 in words is "one trillion, eighty-one billion, six hundred twenty-one million, eight hundred one thousand, six hundred sixty-seven".