20442555 has 72 divisors (see below), whose sum is σ = 42112512. Its totient is φ = 9144576.

The previous prime is 20442523. The next prime is 20442557. The reversal of 20442555 is 55524402.

It is not a de Polignac number, because 20442555 - 2⁵ = 20442523 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20442557) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 160902 + ... + 161028.

It is an arithmetic number, because the mean of its divisors is an integer number (584896).

Almost surely, 2^20442555 is an apocalyptic number.

20442555 is an abundant number, since it is smaller than the sum of its proper divisors (21669957).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20442555 is a wasteful number, since it uses less digits than its factorization.

With its successor (20442556) it forms an eRAP, since the sums of their prime factors are consecutive (225 and 226).

20442555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225 (or 215 counting only the distinct ones).

The product of its (nonzero) digits is 8000, while the sum is 27.

The square root of 20442555 is about 4521.3443797172. The cubic root of 20442555 is about 273.4293048211.

Adding to 20442555 its reverse (55524402), we get a palindrome (75966957).

It can be divided in two parts, 204425 and 55, that added together give a triangular number (204480 = T₆₃₉).

The spelling of 20442555 in words is "twenty million, four hundred forty-two thousand, five hundred fifty-five".