21221523051663 has 64 divisors (see below), whose sum is σ = 32786584934400. Its totient is φ = 12074506704000.

The previous prime is 21221523051607. The next prime is 21221523051697. The reversal of 21221523051663 is 36615032512212.

It is not a de Polignac number, because 21221523051663 - 2⁹ = 21221523051151 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221523031663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 58052928 + ... + 58417338.

It is an arithmetic number, because the mean of its divisors is an integer number (512290389600).

Almost surely, 2^{21221523051663} is an apocalyptic number.

21221523051663 is a deficient number, since it is larger than the sum of its proper divisors (11565061882737).

21221523051663 is a wasteful number, since it uses less digits than its factorization.

21221523051663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 365284.

The product of its (nonzero) digits is 129600, while the sum is 39.

Adding to 21221523051663 its reverse (36615032512212), we get a palindrome (57836555563875).

The spelling of 21221523051663 in words is "twenty-one trillion, two hundred twenty-one billion, five hundred twenty-three million, fifty-one thousand, six hundred sixty-three".