21500442140451 has 64 divisors (see below), whose sum is σ = 29933820864000. Its totient is φ = 13715295998976.

The previous prime is 21500442140447. The next prime is 21500442140479. The reversal of 21500442140451 is 15404124400512.

It is not a de Polignac number, because 21500442140451 - 2² = 21500442140447 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21500442140431) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 6075285640 + ... + 6075289178.

It is an arithmetic number, because the mean of its divisors is an integer number (467715951000).

Almost surely, 2^{21500442140451} is an apocalyptic number.

21500442140451 is a deficient number, since it is larger than the sum of its proper divisors (8433378723549).

21500442140451 is a wasteful number, since it uses less digits than its factorization.

21500442140451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7268.

The product of its (nonzero) digits is 25600, while the sum is 33.

Adding to 21500442140451 its reverse (15404124400512), we get a palindrome (36904566540963).

The spelling of 21500442140451 in words is "twenty-one trillion, five hundred billion, four hundred forty-two million, one hundred forty thousand, four hundred fifty-one".