155565623 has 4 divisors (see below), whose sum is σ = 164716560. Its totient is φ = 146414688.

The previous prime is 155565617. The next prime is 155565637. The reversal of 155565623 is 326565551.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 326565551 = 13 ⋅25120427.

It is a cyclic number.

It is not a de Polignac number, because 155565623 - 2⁴ = 155565607 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 (155595623) 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, 4575443 + ... + 4575476.

It is an arithmetic number, because the mean of its divisors is an integer number (41179140).

Almost surely, 2^155565623 is an apocalyptic number.

155565623 is a deficient number, since it is larger than the sum of its proper divisors (9150937).

155565623 is an equidigital number, since it uses as much as digits as its factorization.

155565623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9150936.

The product of its digits is 135000, while the sum is 38.

The square root of 155565623 is about 12472.5948783723. The cubic root of 155565623 is about 537.8211506412.

The spelling of 155565623 in words is "one hundred fifty-five million, five hundred sixty-five thousand, six hundred twenty-three".