21036791245 has 4 divisors (see below), whose sum is σ = 25244149500. Its totient is φ = 16829432992.

The previous prime is 21036791227. The next prime is 21036791261. The reversal of 21036791245 is 54219763012.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 14735289321 + 6301501924 = 121389^2 + 79382^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21036791245 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21036791198 and 21036791207.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2103679120 + ... + 2103679129.

It is an arithmetic number, because the mean of its divisors is an integer number (6311037375).

Almost surely, 2^21036791245 is an apocalyptic number.

It is an amenable number.

21036791245 is a deficient number, since it is larger than the sum of its proper divisors (4207358255).

21036791245 is an equidigital number, since it uses as much as digits as its factorization.

21036791245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4207358254.

The product of its (nonzero) digits is 90720, while the sum is 40.

The spelling of 21036791245 in words is "twenty-one billion, thirty-six million, seven hundred ninety-one thousand, two hundred forty-five".