16421644575 has 54 divisors (see below), whose sum is σ = 33625259304. Its totient is φ = 7504712640.

The previous prime is 16421644559. The next prime is 16421644609. The reversal of 16421644575 is 57544612461.

16421644575 is a `hidden beast` number, since 1 + 64 + 2 + 16 + 4 + 4 + 575 = 666.

It is not a de Polignac number, because 16421644575 - 2⁴ = 16421644559 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 16421644575.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 5084061 + ... + 5087289.

Almost surely, 2^16421644575 is an apocalyptic number.

16421644575 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

16421644575 is an abundant number, since it is smaller than the sum of its proper divisors (17203614729).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

16421644575 is an frugal number, since it uses more digits than its factorization.

16421644575 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6481 (or 3244 counting only the distinct ones).

The product of its digits is 806400, while the sum is 45.

The spelling of 16421644575 in words is "sixteen billion, four hundred twenty-one million, six hundred forty-four thousand, five hundred seventy-five".