21450420365 has 16 divisors (see below), whose sum is σ = 28086587136. Its totient is φ = 15596952000.

The previous prime is 21450420359. The next prime is 21450420371. The reversal of 21450420365 is 56302405412.

It is an interprime number because it is at equal distance from previous prime (21450420359) and next prime (21450420371).

It is not a de Polignac number, because 21450420365 - 2¹⁴ = 21450403981 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 (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 232415 + ... + 311315.

It is an arithmetic number, because the mean of its divisors is an integer number (1755411696).

Almost surely, 2^21450420365 is an apocalyptic number.

It is an amenable number.

21450420365 is a deficient number, since it is larger than the sum of its proper divisors (6636166771).

21450420365 is a wasteful number, since it uses less digits than its factorization.

21450420365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83860.

The product of its (nonzero) digits is 28800, while the sum is 32.

Adding to 21450420365 its reverse (56302405412), we get a palindrome (77752825777).

The spelling of 21450420365 in words is "twenty-one billion, four hundred fifty million, four hundred twenty thousand, three hundred sixty-five".