81354761 has 2 divisors, whose sum is σ = 81354762. Its totient is φ = 81354760.

The previous prime is 81354743. The next prime is 81354781. The reversal of 81354761 is 16745318.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76667536 + 4687225 = 8756^2 + 2165^2 .

It is a cyclic number.

It is not a de Polignac number, because 81354761 - 2¹⁴ = 81338377 is a prime.

It is not a weakly prime, because it can be changed into another prime (81354781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40677380 + 40677381.

It is an arithmetic number, because the mean of its divisors is an integer number (40677381).

Almost surely, 2^81354761 is an apocalyptic number.

It is an amenable number.

81354761 is a deficient number, since it is larger than the sum of its proper divisors (1).

81354761 is an equidigital number, since it uses as much as digits as its factorization.

81354761 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20160, while the sum is 35.

The square root of 81354761 is about 9019.6874114351. The cubic root of 81354761 is about 433.3056226198.

The spelling of 81354761 in words is "eighty-one million, three hundred fifty-four thousand, seven hundred sixty-one".