21045730745 has 32 divisors (see below), whose sum is σ = 27570117120. Its totient is φ = 15328984320.

The previous prime is 21045730729. The next prime is 21045730751. The reversal of 21045730745 is 54703754012.

It is not a de Polignac number, because 21045730745 - 2⁴ = 21045730729 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21045730699 and 21045730708.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7860347 + ... + 7863023.

It is an arithmetic number, because the mean of its divisors is an integer number (861566160).

Almost surely, 2^21045730745 is an apocalyptic number.

It is an amenable number.

21045730745 is a deficient number, since it is larger than the sum of its proper divisors (6524386375).

21045730745 is a wasteful number, since it uses less digits than its factorization.

21045730745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4305.

The product of its (nonzero) digits is 117600, while the sum is 38.

The spelling of 21045730745 in words is "twenty-one billion, forty-five million, seven hundred thirty thousand, seven hundred forty-five".