81369123 has 16 divisors (see below), whose sum is σ = 125318016. Its totient is φ = 46413440.

The previous prime is 81369121. The next prime is 81369137. The reversal of 81369123 is 32196318.

It is a cyclic number.

It is not a de Polignac number, because 81369123 - 2¹ = 81369121 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (81369121) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 71961 + ... + 73082.

It is an arithmetic number, because the mean of its divisors is an integer number (7832376).

Almost surely, 2^81369123 is an apocalyptic number.

81369123 is a deficient number, since it is larger than the sum of its proper divisors (43948893).

81369123 is a wasteful number, since it uses less digits than its factorization.

81369123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145074.

The product of its digits is 7776, while the sum is 33.

The square root of 81369123 is about 9020.4835236255. The cubic root of 81369123 is about 433.3311190551.

The spelling of 81369123 in words is "eighty-one million, three hundred sixty-nine thousand, one hundred twenty-three".