81423061 has 4 divisors (see below), whose sum is σ = 82262572. Its totient is φ = 80583552.

The previous prime is 81423053. The next prime is 81423071. The reversal of 81423061 is 16032418.

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

It can be written as a sum of positive squares in 2 ways, for example, as 45495025 + 35928036 = 6745^2 + 5994^2 .

It is a cyclic number.

It is not a de Polignac number, because 81423061 - 2³ = 81423053 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81423071) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 419610 + ... + 419803.

It is an arithmetic number, because the mean of its divisors is an integer number (20565643).

Almost surely, 2^81423061 is an apocalyptic number.

It is an amenable number.

81423061 is a deficient number, since it is larger than the sum of its proper divisors (839511).

81423061 is an equidigital number, since it uses as much as digits as its factorization.

81423061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 839510.

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 81423061 is about 9023.4727793683. The cubic root of 81423061 is about 433.4268468137.

Adding to 81423061 its reverse (16032418), we get a palindrome (97455479).

The spelling of 81423061 in words is "eighty-one million, four hundred twenty-three thousand, sixty-one".