821381091511 has 2 divisors, whose sum is σ = 821381091512. Its totient is φ = 821381091510.

The previous prime is 821381091473. The next prime is 821381091529. The reversal of 821381091511 is 115190183128.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 821381091511 - 2²³ = 821372702903 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (821381091541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410690545755 + 410690545756.

It is an arithmetic number, because the mean of its divisors is an integer number (410690545756).

Almost surely, 2^821381091511 is an apocalyptic number.

821381091511 is a deficient number, since it is larger than the sum of its proper divisors (1).

821381091511 is an equidigital number, since it uses as much as digits as its factorization.

821381091511 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17280, while the sum is 40.

The spelling of 821381091511 in words is "eight hundred twenty-one billion, three hundred eighty-one million, ninety-one thousand, five hundred eleven".