21451242301451 has 4 divisors (see below), whose sum is σ = 21488419498392. Its totient is φ = 21414065104512.

The previous prime is 21451242301439. The next prime is 21451242301453. The reversal of 21451242301451 is 15410324215412.

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 21451242301451 - 2⁶ = 21451242301387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21451242301453) 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, 18588597605 + ... + 18588598758.

It is an arithmetic number, because the mean of its divisors is an integer number (5372104874598).

Almost surely, 2^{21451242301451} is an apocalyptic number.

21451242301451 is a deficient number, since it is larger than the sum of its proper divisors (37177196941).

21451242301451 is an equidigital number, since it uses as much as digits as its factorization.

21451242301451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37177196940.

The product of its (nonzero) digits is 38400, while the sum is 35.

Adding to 21451242301451 its reverse (15410324215412), we get a palindrome (36861566516863).

The spelling of 21451242301451 in words is "twenty-one trillion, four hundred fifty-one billion, two hundred forty-two million, three hundred one thousand, four hundred fifty-one".