21321456051 has 8 divisors (see below), whose sum is σ = 32489837824. Its totient is φ = 12183689160.

The previous prime is 21321456041. The next prime is 21321456059. The reversal of 21321456051 is 15065412312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21321456051 - 2⁷ = 21321455923 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21321456059) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 507653695 + ... + 507653736.

It is an arithmetic number, because the mean of its divisors is an integer number (4061229728).

Almost surely, 2^21321456051 is an apocalyptic number.

21321456051 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21321456051 is a deficient number, since it is larger than the sum of its proper divisors (11168381773).

21321456051 is a wasteful number, since it uses less digits than its factorization.

21321456051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1015307441.

The product of its (nonzero) digits is 7200, while the sum is 30.

Adding to 21321456051 its reverse (15065412312), we get a palindrome (36386868363).

The spelling of 21321456051 in words is "twenty-one billion, three hundred twenty-one million, four hundred fifty-six thousand, fifty-one".