19702736645 has 4 divisors (see below), whose sum is σ = 23643283980. Its totient is φ = 15762189312.

The previous prime is 19702736639. The next prime is 19702736737. The reversal of 19702736645 is 54663720791.

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 4864086049 + 14838650596 = 69743^2 + 121814^2 .

It is a cyclic number.

It is not a de Polignac number, because 19702736645 - 2¹² = 19702732549 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 19702736593 and 19702736602.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1970273660 + ... + 1970273669.

It is an arithmetic number, because the mean of its divisors is an integer number (5910820995).

Almost surely, 2^19702736645 is an apocalyptic number.

It is an amenable number.

19702736645 is a deficient number, since it is larger than the sum of its proper divisors (3940547335).

19702736645 is an equidigital number, since it uses as much as digits as its factorization.

19702736645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3940547334.

The product of its (nonzero) digits is 1905120, while the sum is 50.

The spelling of 19702736645 in words is "nineteen billion, seven hundred two million, seven hundred thirty-six thousand, six hundred forty-five".