21452782727378 has 6 divisors (see below), whose sum is σ = 32179183916421. Its totient is φ = 10726388088572.

The previous prime is 21452782727351. The next prime is 21452782727417. The reversal of 21452782727378 is 87372728725412.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20314428165409 + 1138354561969 = 4507153^2 + 1066937^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=3275117.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 4912676 + ... + 8187792.

Almost surely, 2^{21452782727378} is an apocalyptic number.

21452782727378 is a deficient number, since it is larger than the sum of its proper divisors (10726401189043).

21452782727378 is an frugal number, since it uses more digits than its factorization.

21452782727378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6550236 (or 3275119 counting only the distinct ones).

The product of its digits is 147517440, while the sum is 65.

The spelling of 21452782727378 in words is "twenty-one trillion, four hundred fifty-two billion, seven hundred eighty-two million, seven hundred twenty-seven thousand, three hundred seventy-eight".