19963702561 has 4 divisors (see below), whose sum is σ = 21778584624. Its totient is φ = 18148820500.

The previous prime is 19963702547. The next prime is 19963702567. The reversal of 19963702561 is 16520736991.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 19963702561 - 2¹⁷ = 19963571489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19963702567) by changing a digit.

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, 907441015 + ... + 907441036.

It is an arithmetic number, because the mean of its divisors is an integer number (5444646156).

Almost surely, 2^19963702561 is an apocalyptic number.

19963702561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

19963702561 is a deficient number, since it is larger than the sum of its proper divisors (1814882063).

19963702561 is a wasteful number, since it uses less digits than its factorization.

19963702561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1814882062.

The product of its (nonzero) digits is 612360, while the sum is 49.

The spelling of 19963702561 in words is "nineteen billion, nine hundred sixty-three million, seven hundred two thousand, five hundred sixty-one".