21097889105 has 16 divisors (see below), whose sum is σ = 25640544384. Its totient is φ = 16663213440.

The previous prime is 21097889041. The next prime is 21097889107. The reversal of 21097889105 is 50198879012.

It is not a de Polignac number, because 21097889105 - 2⁶ = 21097889041 is a prime.

It is a super-3 number, since 3×21097889105³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21097889107) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 597452 + ... + 631778.

It is an arithmetic number, because the mean of its divisors is an integer number (1602534024).

Almost surely, 2^21097889105 is an apocalyptic number.

It is an amenable number.

21097889105 is a deficient number, since it is larger than the sum of its proper divisors (4542655279).

21097889105 is a wasteful number, since it uses less digits than its factorization.

21097889105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35896.

The product of its (nonzero) digits is 362880, while the sum is 50.

The spelling of 21097889105 in words is "twenty-one billion, ninety-seven million, eight hundred eighty-nine thousand, one hundred five".