21420450063 has 12 divisors (see below), whose sum is σ = 30950351640. Its totient is φ = 14275822416.

The previous prime is 21420450049. The next prime is 21420450067. The reversal of 21420450063 is 36005402412.

It is not a de Polignac number, because 21420450063 - 2⁵ = 21420450031 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21420450067) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 342708 + ... + 400361.

It is an arithmetic number, because the mean of its divisors is an integer number (2579195970).

Almost surely, 2^21420450063 is an apocalyptic number.

21420450063 is a deficient number, since it is larger than the sum of its proper divisors (9529901577).

21420450063 is a wasteful number, since it uses less digits than its factorization.

21420450063 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 746278 (or 746275 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

Adding to 21420450063 its reverse (36005402412), we get a palindrome (57425852475).

The spelling of 21420450063 in words is "twenty-one billion, four hundred twenty million, four hundred fifty thousand, sixty-three".