16491743985 has 16 divisors (see below), whose sum is σ = 26446907520. Its totient is φ = 8775557760.

The previous prime is 16491743977. The next prime is 16491744023. The reversal of 16491743985 is 58934719461.

It is a happy number.

It is not a de Polignac number, because 16491743985 - 2³ = 16491743977 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1245636 + ... + 1258805.

It is an arithmetic number, because the mean of its divisors is an integer number (1652931720).

Almost surely, 2^16491743985 is an apocalyptic number.

16491743985 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

16491743985 is a deficient number, since it is larger than the sum of its proper divisors (9955163535).

16491743985 is a wasteful number, since it uses less digits than its factorization.

16491743985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2504888.

The product of its digits is 6531840, while the sum is 57.

The spelling of 16491743985 in words is "sixteen billion, four hundred ninety-one million, seven hundred forty-three thousand, nine hundred eighty-five".