21445051405 has 4 divisors (see below), whose sum is σ = 25734061692. Its totient is φ = 17156041120.

The previous prime is 21445051393. The next prime is 21445051417. The reversal of 21445051405 is 50415054412.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21445051393) and next prime (21445051417).

It can be written as a sum of positive squares in 2 ways, for example, as 10082770569 + 11362280836 = 100413^2 + 106594^2 .

It is not a de Polignac number, because 21445051405 - 2¹¹ = 21445049357 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2144505136 + ... + 2144505145.

It is an arithmetic number, because the mean of its divisors is an integer number (6433515423).

Almost surely, 2^21445051405 is an apocalyptic number.

It is an amenable number.

21445051405 is a deficient number, since it is larger than the sum of its proper divisors (4289010287).

21445051405 is an equidigital number, since it uses as much as digits as its factorization.

21445051405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4289010286.

The product of its (nonzero) digits is 16000, while the sum is 31.

The spelling of 21445051405 in words is "twenty-one billion, four hundred forty-five million, fifty-one thousand, four hundred five".