20449042638 has 16 divisors (see below), whose sum is σ = 43050616320. Its totient is φ = 6457592376.

The previous prime is 20449042631. The next prime is 20449042661. The reversal of 20449042638 is 83624094402.

It is a super-3 number, since 3×20449042638³ (a number of 32 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20449042638.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20449042631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 89688670 + ... + 89688897.

It is an arithmetic number, because the mean of its divisors is an integer number (2690663520).

Almost surely, 2^20449042638 is an apocalyptic number.

20449042638 is an abundant number, since it is smaller than the sum of its proper divisors (22601573682).

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

20449042638 is a wasteful number, since it uses less digits than its factorization.

20449042638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179377591.

The product of its (nonzero) digits is 331776, while the sum is 42.

The spelling of 20449042638 in words is "twenty billion, four hundred forty-nine million, forty-two thousand, six hundred thirty-eight".