1881320997547 has 4 divisors (see below), whose sum is σ = 1889192633760. Its totient is φ = 1873449361336.

The previous prime is 1881320997511. The next prime is 1881320997637. The reversal of 1881320997547 is 7457990231881.

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

It is a cyclic number.

It is not a de Polignac number, because 1881320997547 - 2¹⁵ = 1881320964779 is a prime.

It is a super-2 number, since 2×1881320997547² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1881320997847) 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, 3935817748 + ... + 3935818225.

It is an arithmetic number, because the mean of its divisors is an integer number (472298158440).

Almost surely, 2^{1881320997547} is an apocalyptic number.

1881320997547 is a deficient number, since it is larger than the sum of its proper divisors (7871636213).

1881320997547 is an equidigital number, since it uses as much as digits as its factorization.

1881320997547 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7871636212.

The product of its (nonzero) digits is 30481920, while the sum is 64.

The spelling of 1881320997547 in words is "one trillion, eight hundred eighty-one billion, three hundred twenty million, nine hundred ninety-seven thousand, five hundred forty-seven".