16421907993 has 16 divisors (see below), whose sum is σ = 23059682880. Its totient is φ = 10366605504.

The previous prime is 16421907973. The next prime is 16421908001. The reversal of 16421907993 is 39970912461.

It is not a de Polignac number, because 16421907993 - 2²⁰ = 16420859417 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (16421907973) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 46855 + ... + 187187.

It is an arithmetic number, because the mean of its divisors is an integer number (1441230180).

Almost surely, 2^16421907993 is an apocalyptic number.

It is an amenable number.

16421907993 is a deficient number, since it is larger than the sum of its proper divisors (6637774887).

16421907993 is a wasteful number, since it uses less digits than its factorization.

16421907993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142408.

The product of its (nonzero) digits is 734832, while the sum is 51.

The spelling of 16421907993 in words is "sixteen billion, four hundred twenty-one million, nine hundred seven thousand, nine hundred ninety-three".