21021440413 has 2 divisors, whose sum is σ = 21021440414. Its totient is φ = 21021440412.

The previous prime is 21021440371. The next prime is 21021440417. The reversal of 21021440413 is 31404412012.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18877935609 + 2143504804 = 137397^2 + 46298^2 .

It is a cyclic number.

It is not a de Polignac number, because 21021440413 - 2¹³ = 21021432221 is a prime.

It is a super-2 number, since 2×21021440413² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21021440417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510720206 + 10510720207.

It is an arithmetic number, because the mean of its divisors is an integer number (10510720207).

Almost surely, 2^21021440413 is an apocalyptic number.

It is an amenable number.

21021440413 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021440413 is an equidigital number, since it uses as much as digits as its factorization.

21021440413 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 768, while the sum is 22.

Adding to 21021440413 its reverse (31404412012), we get a palindrome (52425852425).

The spelling of 21021440413 in words is "twenty-one billion, twenty-one million, four hundred forty thousand, four hundred thirteen".