81377033 has 2 divisors, whose sum is σ = 81377034. Its totient is φ = 81377032.

The previous prime is 81377029. The next prime is 81377039. The reversal of 81377033 is 33077318.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 80227849 + 1149184 = 8957^2 + 1072^2 .

It is a cyclic number.

It is not a de Polignac number, because 81377033 - 2² = 81377029 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81377039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40688516 + 40688517.

It is an arithmetic number, because the mean of its divisors is an integer number (40688517).

Almost surely, 2^81377033 is an apocalyptic number.

It is an amenable number.

81377033 is a deficient number, since it is larger than the sum of its proper divisors (1).

81377033 is an equidigital number, since it uses as much as digits as its factorization.

81377033 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10584, while the sum is 32.

The square root of 81377033 is about 9020.9219595338. The cubic root of 81377033 is about 433.3451601637.

The spelling of 81377033 in words is "eighty-one million, three hundred seventy-seven thousand, thirty-three".