1891481380609 has 16 divisors (see below), whose sum is σ = 2038188672000. Its totient is φ = 1749891934800.

The previous prime is 1891481380567. The next prime is 1891481380669. The reversal of 1891481380609 is 9060831841981.

It is a cyclic number.

It is not a de Polignac number, because 1891481380609 - 2¹⁵ = 1891481347841 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1891481380669) 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, 5417869 + ... + 5756410.

It is an arithmetic number, because the mean of its divisors is an integer number (127386792000).

Almost surely, 2^{1891481380609} is an apocalyptic number.

1891481380609 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

1891481380609 is a deficient number, since it is larger than the sum of its proper divisors (146707291391).

1891481380609 is a wasteful number, since it uses less digits than its factorization.

1891481380609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11174508.

The product of its (nonzero) digits is 2985984, while the sum is 58.

The spelling of 1891481380609 in words is "one trillion, eight hundred ninety-one billion, four hundred eighty-one million, three hundred eighty thousand, six hundred nine".