21221451420501 has 32 divisors (see below), whose sum is σ = 29003998531968. Its totient is φ = 13797501062400.

The previous prime is 21221451420461. The next prime is 21221451420529. The reversal of 21221451420501 is 10502415412212.

It is not a de Polignac number, because 21221451420501 - 2⁷ = 21221451420373 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221451420901) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 375885391 + ... + 375941843.

It is an arithmetic number, because the mean of its divisors is an integer number (906374954124).

Almost surely, 2^{21221451420501} is an apocalyptic number.

It is an amenable number.

21221451420501 is a deficient number, since it is larger than the sum of its proper divisors (7782547111467).

21221451420501 is a wasteful number, since it uses less digits than its factorization.

21221451420501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75141.

The product of its (nonzero) digits is 6400, while the sum is 30.

Adding to 21221451420501 its reverse (10502415412212), we get a palindrome (31723866832713).

The spelling of 21221451420501 in words is "twenty-one trillion, two hundred twenty-one billion, four hundred fifty-one million, four hundred twenty thousand, five hundred one".