21790813427 has 2 divisors, whose sum is σ = 21790813428. Its totient is φ = 21790813426.

The previous prime is 21790813409. The next prime is 21790813453. The reversal of 21790813427 is 72431809712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21790813427 - 2¹⁰ = 21790812403 is a prime.

It is not a weakly prime, because it can be changed into another prime (21790813487) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10895406713 + 10895406714.

It is an arithmetic number, because the mean of its divisors is an integer number (10895406714).

Almost surely, 2^21790813427 is an apocalyptic number.

21790813427 is a deficient number, since it is larger than the sum of its proper divisors (1).

21790813427 is an equidigital number, since it uses as much as digits as its factorization.

21790813427 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 169344, while the sum is 44.

The spelling of 21790813427 in words is "twenty-one billion, seven hundred ninety million, eight hundred thirteen thousand, four hundred twenty-seven".