21155554086 has 32 divisors (see below), whose sum is σ = 44808564960. Its totient is φ = 6635767296.

The previous prime is 21155554081. The next prime is 21155554093. The reversal of 21155554086 is 68045555112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21155554081) 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 15 ways as a sum of consecutive naturals, for example, 615360 + ... + 648828.

It is an arithmetic number, because the mean of its divisors is an integer number (1400267655).

Almost surely, 2^21155554086 is an apocalyptic number.

21155554086 is an abundant number, since it is smaller than the sum of its proper divisors (23653010874).

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

21155554086 is a wasteful number, since it uses less digits than its factorization.

21155554086 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39688.

The product of its (nonzero) digits is 240000, while the sum is 42.

The spelling of 21155554086 in words is "twenty-one billion, one hundred fifty-five million, five hundred fifty-four thousand, eighty-six".