81148369 has 2 divisors, whose sum is σ = 81148370. Its totient is φ = 81148368.

The previous prime is 81148337. The next prime is 81148399. The reversal of 81148369 is 96384118.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59105344 + 22043025 = 7688^2 + 4695^2 .

It is a cyclic number.

It is not a de Polignac number, because 81148369 - 2⁵ = 81148337 is a prime.

It is a super-2 number, since 2×81148369² = 13170115582720322, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81148399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40574184 + 40574185.

It is an arithmetic number, because the mean of its divisors is an integer number (40574185).

Almost surely, 2^81148369 is an apocalyptic number.

It is an amenable number.

81148369 is a deficient number, since it is larger than the sum of its proper divisors (1).

81148369 is an equidigital number, since it uses as much as digits as its factorization.

81148369 is an evil number, because the sum of its binary digits is even.

The product of its digits is 41472, while the sum is 40.

The square root of 81148369 is about 9008.2389510936. The cubic root of 81148369 is about 432.9388891243.

The spelling of 81148369 in words is "eighty-one million, one hundred forty-eight thousand, three hundred sixty-nine".