21100970945 has 16 divisors (see below), whose sum is σ = 26815276800. Its totient is φ = 15885045504.

The previous prime is 21100970941. The next prime is 21100971007. The reversal of 21100970945 is 54907900112.

It is a cyclic number.

It is not a de Polignac number, because 21100970945 - 2² = 21100970941 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21100970899 and 21100970908.

It is not an unprimeable number, because it can be changed into a prime (21100970941) 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, 568424 + ... + 604406.

It is an arithmetic number, because the mean of its divisors is an integer number (1675954800).

Almost surely, 2^21100970945 is an apocalyptic number.

It is an amenable number.

21100970945 is a deficient number, since it is larger than the sum of its proper divisors (5714305855).

21100970945 is a wasteful number, since it uses less digits than its factorization.

21100970945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42904.

The product of its (nonzero) digits is 22680, while the sum is 38.

The spelling of 21100970945 in words is "twenty-one billion, one hundred million, nine hundred seventy thousand, nine hundred forty-five".