20858542878 has 16 divisors (see below), whose sum is σ = 41761429776. Its totient is φ = 6945456960.

The previous prime is 20858542843. The next prime is 20858542879. The reversal of 20858542878 is 87824585802.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20858542879) 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, 1841551 + ... + 1852842.

It is an arithmetic number, because the mean of its divisors is an integer number (2610089361).

Almost surely, 2^20858542878 is an apocalyptic number.

20858542878 is an abundant number, since it is smaller than the sum of its proper divisors (20902886898).

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

20858542878 is a wasteful number, since it uses less digits than its factorization.

20858542878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3695339.

The product of its (nonzero) digits is 11468800, while the sum is 57.

The spelling of 20858542878 in words is "twenty billion, eight hundred fifty-eight million, five hundred forty-two thousand, eight hundred seventy-eight".