42645623 has 2 divisors, whose sum is σ = 42645624. Its totient is φ = 42645622.

The previous prime is 42645607. The next prime is 42645643. The reversal of 42645623 is 32654624.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 42645623 - 2⁴ = 42645607 is a prime.

It is a super-2 number, since 2×42645623² = 3637298322116258, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 42645623.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42645643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21322811 + 21322812.

It is an arithmetic number, because the mean of its divisors is an integer number (21322812).

Almost surely, 2^42645623 is an apocalyptic number.

42645623 is a deficient number, since it is larger than the sum of its proper divisors (1).

42645623 is an equidigital number, since it uses as much as digits as its factorization.

42645623 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34560, while the sum is 32.

The square root of 42645623 is about 6530.3616285777. The cubic root of 42645623 is about 349.3747285219.

Subtracting from 42645623 its reverse (32654624), we obtain a palindrome (9990999).

The spelling of 42645623 in words is "forty-two million, six hundred forty-five thousand, six hundred twenty-three".