21021440371 has 2 divisors, whose sum is σ = 21021440372. Its totient is φ = 21021440370.

The previous prime is 21021440317. The next prime is 21021440413. The reversal of 21021440371 is 17304412012.

Together with previous prime (21021440317) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21021440371 - 2²⁹ = 20484569459 is a prime.

It is not a weakly prime, because it can be changed into another prime (21021440071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510720185 + 10510720186.

It is an arithmetic number, because the mean of its divisors is an integer number (10510720186).

Almost surely, 2^21021440371 is an apocalyptic number.

21021440371 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021440371 is an equidigital number, since it uses as much as digits as its factorization.

21021440371 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1344, while the sum is 25.

Adding to 21021440371 its reverse (17304412012), we get a palindrome (38325852383).

The spelling of 21021440371 in words is "twenty-one billion, twenty-one million, four hundred forty thousand, three hundred seventy-one".