81155411 has 2 divisors, whose sum is σ = 81155412. Its totient is φ = 81155410.

The previous prime is 81155407. The next prime is 81155423. The reversal of 81155411 is 11455118.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81155411 - 2² = 81155407 is a prime.

It is not a weakly prime, because it can be changed into another prime (81155401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40577705 + 40577706.

It is an arithmetic number, because the mean of its divisors is an integer number (40577706).

Almost surely, 2^81155411 is an apocalyptic number.

81155411 is a deficient number, since it is larger than the sum of its proper divisors (1).

81155411 is an equidigital number, since it uses as much as digits as its factorization.

81155411 is an evil number, because the sum of its binary digits is even.

The product of its digits is 800, while the sum is 26.

The square root of 81155411 is about 9008.6298070239. The cubic root of 81155411 is about 432.9514121423.

The spelling of 81155411 in words is "eighty-one million, one hundred fifty-five thousand, four hundred eleven".