21201321441 has 32 divisors (see below), whose sum is σ = 29663682048. Its totient is φ = 13454098560.

The previous prime is 21201321439. The next prime is 21201321517. The reversal of 21201321441 is 14412310212.

It is not a de Polignac number, because 21201321441 - 2¹ = 21201321439 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21201326441) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6911190 + ... + 6914256.

It is an arithmetic number, because the mean of its divisors is an integer number (926990064).

Almost surely, 2^21201321441 is an apocalyptic number.

It is an amenable number.

21201321441 is a deficient number, since it is larger than the sum of its proper divisors (8462360607).

21201321441 is a wasteful number, since it uses less digits than its factorization.

21201321441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4461.

The product of its (nonzero) digits is 384, while the sum is 21.

Adding to 21201321441 its reverse (14412310212), we get a palindrome (35613631653).

The spelling of 21201321441 in words is "twenty-one billion, two hundred one million, three hundred twenty-one thousand, four hundred forty-one".