19530221649 has 4 divisors (see below), whose sum is σ = 26040295536. Its totient is φ = 13020147764.

The previous prime is 19530221647. The next prime is 19530221653. The reversal of 19530221649 is 94612203591.

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 19530221649 - 2¹ = 19530221647 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19530221649.

It is not an unprimeable number, because it can be changed into a prime (19530221647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3255036939 + ... + 3255036944.

It is an arithmetic number, because the mean of its divisors is an integer number (6510073884).

Almost surely, 2^19530221649 is an apocalyptic number.

It is an amenable number.

19530221649 is a deficient number, since it is larger than the sum of its proper divisors (6510073887).

19530221649 is an equidigital number, since it uses as much as digits as its factorization.

19530221649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6510073886.

The product of its (nonzero) digits is 116640, while the sum is 42.

The spelling of 19530221649 in words is "nineteen billion, five hundred thirty million, two hundred twenty-one thousand, six hundred forty-nine".