16421666531 has 8 divisors (see below), whose sum is σ = 16454407200. Its totient is φ = 16388951040.

The previous prime is 16421666489. The next prime is 16421666539. The reversal of 16421666531 is 13566612461.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 16421666531 - 2¹⁸ = 16421404387 is a prime.

It is a super-2 number, since 2×16421666531² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16421666539) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1772810 + ... + 1782048.

It is an arithmetic number, because the mean of its divisors is an integer number (2056800900).

Almost surely, 2^16421666531 is an apocalyptic number.

16421666531 is a deficient number, since it is larger than the sum of its proper divisors (32740669).

16421666531 is an equidigital number, since it uses as much as digits as its factorization.

16421666531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12589.

The product of its digits is 155520, while the sum is 41.

The spelling of 16421666531 in words is "sixteen billion, four hundred twenty-one million, six hundred sixty-six thousand, five hundred thirty-one".