21152221031451 has 16 divisors (see below), whose sum is σ = 30711028723200. Its totient is φ = 12898632061728.

The previous prime is 21152221031437. The next prime is 21152221031453. The reversal of 21152221031451 is 15413012225112.

It is not a de Polignac number, because 21152221031451 - 2⁹ = 21152221030939 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21152221031453) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6398129331 + ... + 6398132636.

It is an arithmetic number, because the mean of its divisors is an integer number (1919439295200).

Almost surely, 2^{21152221031451} is an apocalyptic number.

21152221031451 is a deficient number, since it is larger than the sum of its proper divisors (9558807691749).

21152221031451 is a wasteful number, since it uses less digits than its factorization.

21152221031451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12796262018.

The product of its (nonzero) digits is 4800, while the sum is 30.

Adding to 21152221031451 its reverse (15413012225112), we get a palindrome (36565233256563).

The spelling of 21152221031451 in words is "twenty-one trillion, one hundred fifty-two billion, two hundred twenty-one million, thirty-one thousand, four hundred fifty-one".