16445256421 has 32 divisors (see below), whose sum is σ = 18534375936. Its totient is φ = 14464320000.

The previous prime is 16445256419. The next prime is 16445256449. The reversal of 16445256421 is 12465254461.

It is a cyclic number.

It is not a de Polignac number, because 16445256421 - 2¹ = 16445256419 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 (16445256491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 21609681 + ... + 21610441.

It is an arithmetic number, because the mean of its divisors is an integer number (579199248).

Almost surely, 2^16445256421 is an apocalyptic number.

16445256421 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16445256421 is a deficient number, since it is larger than the sum of its proper divisors (2089119515).

16445256421 is a wasteful number, since it uses less digits than its factorization.

16445256421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1293.

The product of its digits is 230400, while the sum is 40.

The spelling of 16445256421 in words is "sixteen billion, four hundred forty-five million, two hundred fifty-six thousand, four hundred twenty-one".