42420155 has 4 divisors (see below), whose sum is σ = 50904192. Its totient is φ = 33936120.

The previous prime is 42420109. The next prime is 42420181. The reversal of 42420155 is 55102424.

It is a happy number.

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

It is not a de Polignac number, because 42420155 - 2²² = 38225851 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 42420155.

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, 4242011 + ... + 4242020.

It is an arithmetic number, because the mean of its divisors is an integer number (12726048).

Almost surely, 2^42420155 is an apocalyptic number.

42420155 is a deficient number, since it is larger than the sum of its proper divisors (8484037).

42420155 is an equidigital number, since it uses as much as digits as its factorization.

42420155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8484036.

The product of its (nonzero) digits is 1600, while the sum is 23.

The square root of 42420155 is about 6513.0756943245. The cubic root of 42420155 is about 348.7579238788.

Adding to 42420155 its reverse (55102424), we get a palindrome (97522579).

The spelling of 42420155 in words is "forty-two million, four hundred twenty thousand, one hundred fifty-five".