21121000464451 has 16 divisors (see below), whose sum is σ = 21546519533568. Its totient is φ = 20699085405600.

The previous prime is 21121000464427. The next prime is 21121000464469. The reversal of 21121000464451 is 15446400012112.

It is a cyclic number.

It is not a de Polignac number, because 21121000464451 - 2¹¹ = 21121000462403 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21121000464401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 63299866 + ... + 63632656.

It is an arithmetic number, because the mean of its divisors is an integer number (1346657470848).

Almost surely, 2^{21121000464451} is an apocalyptic number.

21121000464451 is a deficient number, since it is larger than the sum of its proper divisors (425519069117).

21121000464451 is a wasteful number, since it uses less digits than its factorization.

21121000464451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 338202.

The product of its (nonzero) digits is 7680, while the sum is 31.

Adding to 21121000464451 its reverse (15446400012112), we get a palindrome (36567400476563).

The spelling of 21121000464451 in words is "twenty-one trillion, one hundred twenty-one billion, four hundred sixty-four thousand, four hundred fifty-one".