21221420241 has 24 divisors (see below), whose sum is σ = 33046048224. Its totient is φ = 12078192000.

The previous prime is 21221420191. The next prime is 21221420273. The reversal of 21221420241 is 14202412212.

It is not a de Polignac number, because 21221420241 - 2⁶ = 21221420177 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (21221420141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 250680 + ... + 324473.

It is an arithmetic number, because the mean of its divisors is an integer number (1376918676).

Almost surely, 2^21221420241 is an apocalyptic number.

21221420241 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21221420241 is a deficient number, since it is larger than the sum of its proper divisors (11824627983).

21221420241 is a wasteful number, since it uses less digits than its factorization.

21221420241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 575421 (or 575414 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 21.

Adding to 21221420241 its reverse (14202412212), we get a palindrome (35423832453).

The spelling of 21221420241 in words is "twenty-one billion, two hundred twenty-one million, four hundred twenty thousand, two hundred forty-one".