90105623 has 4 divisors (see below), whose sum is σ = 93012288. Its totient is φ = 87198960.

The previous prime is 90105569. The next prime is 90105643. The reversal of 90105623 is 32650109.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32650109 = 1249 ⋅26141.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-90105623 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 90105592 and 90105601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90105643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1453286 + ... + 1453347.

It is an arithmetic number, because the mean of its divisors is an integer number (23253072).

Almost surely, 2^90105623 is an apocalyptic number.

90105623 is a deficient number, since it is larger than the sum of its proper divisors (2906665).

90105623 is a wasteful number, since it uses less digits than its factorization.

90105623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2906664.

The product of its (nonzero) digits is 1620, while the sum is 26.

The square root of 90105623 is about 9492.3981690614. The cubic root of 90105623 is about 448.3157170133.

The spelling of 90105623 in words is "ninety million, one hundred five thousand, six hundred twenty-three".