21054688867 has 4 divisors (see below), whose sum is σ = 21055002696. Its totient is φ = 21054375040.

The previous prime is 21054688859. The next prime is 21054688901. The reversal of 21054688867 is 76888645012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21054688867 - 2³ = 21054688859 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21054688807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11134 + ... + 205507.

It is an arithmetic number, because the mean of its divisors is an integer number (5263750674).

Almost surely, 2^21054688867 is an apocalyptic number.

21054688867 is a deficient number, since it is larger than the sum of its proper divisors (313829).

21054688867 is an equidigital number, since it uses as much as digits as its factorization.

21054688867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 313828.

The product of its (nonzero) digits is 5160960, while the sum is 55.

The spelling of 21054688867 in words is "twenty-one billion, fifty-four million, six hundred eighty-eight thousand, eight hundred sixty-seven".