1811621781107 has 2 divisors, whose sum is σ = 1811621781108. Its totient is φ = 1811621781106.

The previous prime is 1811621781097. The next prime is 1811621781127. The reversal of 1811621781107 is 7011871261181.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1811621781107 - 2¹⁴ = 1811621764723 is a prime.

It is not a weakly prime, because it can be changed into another prime (1811621781127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 905810890553 + 905810890554.

It is an arithmetic number, because the mean of its divisors is an integer number (905810890554).

Almost surely, 2^{1811621781107} is an apocalyptic number.

1811621781107 is a deficient number, since it is larger than the sum of its proper divisors (1).

1811621781107 is an equidigital number, since it uses as much as digits as its factorization.

1811621781107 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 37632, while the sum is 44.

The spelling of 1811621781107 in words is "one trillion, eight hundred eleven billion, six hundred twenty-one million, seven hundred eighty-one thousand, one hundred seven".