121605623 has 4 divisors (see below), whose sum is σ = 126892848. Its totient is φ = 116318400.

The previous prime is 121605593. The next prime is 121605637. The reversal of 121605623 is 326506121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 326506121 = 109 ⋅2995469.

It is a cyclic number.

It is not a de Polignac number, because 121605623 - 2¹⁴ = 121589239 is a prime.

It is a super-3 number, since 3×121605623³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121605592 and 121605601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121605023) 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, 2643578 + ... + 2643623.

It is an arithmetic number, because the mean of its divisors is an integer number (31723212).

Almost surely, 2^121605623 is an apocalyptic number.

121605623 is a deficient number, since it is larger than the sum of its proper divisors (5287225).

121605623 is an equidigital number, since it uses as much as digits as its factorization.

121605623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5287224.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 121605623 is about 11027.4939582844. The cubic root of 121605623 is about 495.4325681773.

The spelling of 121605623 in words is "one hundred twenty-one million, six hundred five thousand, six hundred twenty-three".