21894891009 has 16 divisors (see below), whose sum is σ = 30467576832. Its totient is φ = 13959613008.

The previous prime is 21894890951. The next prime is 21894891049. The reversal of 21894891009 is 90019849812.

It is not a de Polignac number, because 21894891009 - 2⁷ = 21894890881 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21894891049) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 447534 + ... + 494040.

It is an arithmetic number, because the mean of its divisors is an integer number (1904223552).

Almost surely, 2^21894891009 is an apocalyptic number.

It is an amenable number.

21894891009 is a deficient number, since it is larger than the sum of its proper divisors (8572685823).

21894891009 is a wasteful number, since it uses less digits than its factorization.

21894891009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53356.

The product of its (nonzero) digits is 373248, while the sum is 51.

The spelling of 21894891009 in words is "twenty-one billion, eight hundred ninety-four million, eight hundred ninety-one thousand, nine".