21221354463456 has 96 divisors (see below), whose sum is σ = 63674978411520. Its totient is φ = 6062204606976.

The previous prime is 21221354463427. The next prime is 21221354463467. The reversal of 21221354463456 is 65436445312212.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1219630 + ... + 6627986.

It is an arithmetic number, because the mean of its divisors is an integer number (663281025120).

Almost surely, 2^{21221354463456} is an apocalyptic number.

It is an amenable number.

21221354463456 is an abundant number, since it is smaller than the sum of its proper divisors (42453623948064).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21221354463456 is a wasteful number, since it uses less digits than its factorization.

21221354463456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5414216 (or 5414208 counting only the distinct ones).

The product of its digits is 4147200, while the sum is 48.

Adding to 21221354463456 its reverse (65436445312212), we get a palindrome (86657799775668).

The spelling of 21221354463456 in words is "twenty-one trillion, two hundred twenty-one billion, three hundred fifty-four million, four hundred sixty-three thousand, four hundred fifty-six".