16910631421 has 4 divisors (see below), whose sum is σ = 16911641500. Its totient is φ = 16909621344.

The previous prime is 16910631377. The next prime is 16910631431. The reversal of 16910631421 is 12413601961.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12413601961 = 2549 ⋅4869989.

It can be written as a sum of positive squares in 2 ways, for example, as 6160052196 + 10750579225 = 78486^2 + 103685^2 .

It is a cyclic number.

It is not a de Polignac number, because 16910631421 - 2¹⁷ = 16910500349 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16910631431) 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, 479496 + ... + 513553.

It is an arithmetic number, because the mean of its divisors is an integer number (4227910375).

Almost surely, 2^16910631421 is an apocalyptic number.

It is an amenable number.

16910631421 is a deficient number, since it is larger than the sum of its proper divisors (1010079).

16910631421 is an equidigital number, since it uses as much as digits as its factorization.

16910631421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1010078.

The product of its (nonzero) digits is 7776, while the sum is 34.

The spelling of 16910631421 in words is "sixteen billion, nine hundred ten million, six hundred thirty-one thousand, four hundred twenty-one".