16005431641 has 4 divisors (see below), whose sum is σ = 16847822800. Its totient is φ = 15163040484.

The previous prime is 16005431633. The next prime is 16005431647. The reversal of 16005431641 is 14613450061.

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, and also an emirpimes, since its reverse is a distinct semiprime: 14613450061 = 7 ⋅2087635723.

It is a cyclic number.

It is not a de Polignac number, because 16005431641 - 2³ = 16005431633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16005431647) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 421195551 + ... + 421195588.

It is an arithmetic number, because the mean of its divisors is an integer number (4211955700).

Almost surely, 2^16005431641 is an apocalyptic number.

It is an amenable number.

16005431641 is a deficient number, since it is larger than the sum of its proper divisors (842391159).

16005431641 is an equidigital number, since it uses as much as digits as its factorization.

16005431641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 842391158.

The product of its (nonzero) digits is 8640, while the sum is 31.

The spelling of 16005431641 in words is "sixteen billion, five million, four hundred thirty-one thousand, six hundred forty-one".