16544630421 has 24 divisors (see below), whose sum is σ = 26676620256. Its totient is φ = 9793859040.

The previous prime is 16544630393. The next prime is 16544630423. The reversal of 16544630421 is 12403644561.

16544630421 is a `hidden beast` number, since 16 + 5 + 4 + 4 + 630 + 4 + 2 + 1 = 666.

It is not a de Polignac number, because 16544630421 - 2⁶ = 16544630357 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16544630423) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1938970 + ... + 1947483.

It is an arithmetic number, because the mean of its divisors is an integer number (1111525844).

Almost surely, 2^16544630421 is an apocalyptic number.

16544630421 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16544630421 is a deficient number, since it is larger than the sum of its proper divisors (10131989835).

16544630421 is a wasteful number, since it uses less digits than its factorization.

16544630421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3886513 (or 3886510 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 36.

The spelling of 16544630421 in words is "sixteen billion, five hundred forty-four million, six hundred thirty thousand, four hundred twenty-one".