21542432450451 has 24 divisors (see below), whose sum is σ = 32377841952192. Its totient is φ = 12634857723600.

The previous prime is 21542432450411. The next prime is 21542432450521. The reversal of 21542432450451 is 15405423424512.

It is not a de Polignac number, because 21542432450451 - 2⁶ = 21542432450387 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21542432450411) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 339615001 + ... + 339678426.

It is an arithmetic number, because the mean of its divisors is an integer number (1349076748008).

Almost surely, 2^{21542432450451} is an apocalyptic number.

21542432450451 is a deficient number, since it is larger than the sum of its proper divisors (10835409501741).

21542432450451 is a wasteful number, since it uses less digits than its factorization.

21542432450451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 679293503 (or 679293472 counting only the distinct ones).

The product of its (nonzero) digits is 768000, while the sum is 42.

Adding to 21542432450451 its reverse (15405423424512), we get a palindrome (36947855874963).

The spelling of 21542432450451 in words is "twenty-one trillion, five hundred forty-two billion, four hundred thirty-two million, four hundred fifty thousand, four hundred fifty-one".