21055841718 has 16 divisors (see below), whose sum is σ = 42644743680. Its totient is φ = 6929770536.

The previous prime is 21055841689. The next prime is 21055841747. The reversal of 21055841718 is 81714855012.

It is an interprime number because it is at equal distance from previous prime (21055841689) and next prime (21055841747).

It is a self number, because there is not a number n which added to its sum of digits gives 21055841718.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22210330 + ... + 22211277.

It is an arithmetic number, because the mean of its divisors is an integer number (2665296480).

Almost surely, 2^21055841718 is an apocalyptic number.

21055841718 is an abundant number, since it is smaller than the sum of its proper divisors (21588901962).

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

21055841718 is a wasteful number, since it uses less digits than its factorization.

21055841718 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44421691.

The product of its (nonzero) digits is 89600, while the sum is 42.

The spelling of 21055841718 in words is "twenty-one billion, fifty-five million, eight hundred forty-one thousand, seven hundred eighteen".