81204377 has 2 divisors, whose sum is σ = 81204378. Its totient is φ = 81204376.

The previous prime is 81204373. The next prime is 81204419. The reversal of 81204377 is 77340218.

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., 72318016 + 8886361 = 8504^2 + 2981^2 .

It is a cyclic number.

It is not a de Polignac number, because 81204377 - 2² = 81204373 is a prime.

It is a super-3 number, since 3×81204377³ (a number of 25 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (81204371) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40602188 + 40602189.

It is an arithmetic number, because the mean of its divisors is an integer number (40602189).

Almost surely, 2^81204377 is an apocalyptic number.

It is an amenable number.

81204377 is a deficient number, since it is larger than the sum of its proper divisors (1).

81204377 is an equidigital number, since it uses as much as digits as its factorization.

81204377 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9408, while the sum is 32.

The square root of 81204377 is about 9011.3471245980. The cubic root of 81204377 is about 433.0384699502.

The spelling of 81204377 in words is "eighty-one million, two hundred four thousand, three hundred seventy-seven".