81379511 has 2 divisors, whose sum is σ = 81379512. Its totient is φ = 81379510.

The previous prime is 81379483. The next prime is 81379517. The reversal of 81379511 is 11597318.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81379511 - 2⁶ = 81379447 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81379517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40689755 + 40689756.

It is an arithmetic number, because the mean of its divisors is an integer number (40689756).

Almost surely, 2^81379511 is an apocalyptic number.

81379511 is a deficient number, since it is larger than the sum of its proper divisors (1).

81379511 is an equidigital number, since it uses as much as digits as its factorization.

81379511 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7560, while the sum is 35.

The square root of 81379511 is about 9021.0593058687. The cubic root of 81379511 is about 433.3495586956.

The spelling of 81379511 in words is "eighty-one million, three hundred seventy-nine thousand, five hundred eleven".