81410066 has 4 divisors (see below), whose sum is σ = 122115102. Its totient is φ = 40705032.

The previous prime is 81410057. The next prime is 81410083. The reversal of 81410066 is 66001418.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 80478841 + 931225 = 8971^2 + 965^2 .

It is a super-2 number, since 2×81410066² = 13255197692248712, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20352515 + ... + 20352518.

Almost surely, 2^81410066 is an apocalyptic number.

81410066 is a deficient number, since it is larger than the sum of its proper divisors (40705036).

81410066 is a wasteful number, since it uses less digits than its factorization.

81410066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40705035.

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 81410066 is about 9022.7526841868. The cubic root of 81410066 is about 433.4037874925.

The spelling of 81410066 in words is "eighty-one million, four hundred ten thousand, sixty-six".