423640655 has 4 divisors (see below), whose sum is σ = 508368792. Its totient is φ = 338912520.

The previous prime is 423640649. The next prime is 423640661. The reversal of 423640655 is 556046324.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (423640649) and next prime (423640661).

It is a de Polignac number, because none of the positive numbers 2^k-423640655 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42364061 + ... + 42364070.

It is an arithmetic number, because the mean of its divisors is an integer number (127092198).

Almost surely, 2^423640655 is an apocalyptic number.

423640655 is a deficient number, since it is larger than the sum of its proper divisors (84728137).

423640655 is an equidigital number, since it uses as much as digits as its factorization.

423640655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84728136.

The product of its (nonzero) digits is 86400, while the sum is 35.

The square root of 423640655 is about 20582.5327644583. The cubic root of 423640655 is about 751.0448577611.

Adding to 423640655 its reverse (556046324), we get a palindrome (979686979).

The spelling of 423640655 in words is "four hundred twenty-three million, six hundred forty thousand, six hundred fifty-five".