21201430451 has 4 divisors (see below), whose sum is σ = 21217481304. Its totient is φ = 21185379600.

The previous prime is 21201430447. The next prime is 21201430463. The reversal of 21201430451 is 15403410212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21201430451 - 2² = 21201430447 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21201430351) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8023445 + ... + 8026086.

It is an arithmetic number, because the mean of its divisors is an integer number (5304370326).

Almost surely, 2^21201430451 is an apocalyptic number.

21201430451 is a deficient number, since it is larger than the sum of its proper divisors (16050853).

21201430451 is a wasteful number, since it uses less digits than its factorization.

21201430451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16050852.

The product of its (nonzero) digits is 960, while the sum is 23.

Adding to 21201430451 its reverse (15403410212), we get a palindrome (36604840663).

The spelling of 21201430451 in words is "twenty-one billion, two hundred one million, four hundred thirty thousand, four hundred fifty-one".