21404400937 has 2 divisors, whose sum is σ = 21404400938. Its totient is φ = 21404400936.

The previous prime is 21404400869. The next prime is 21404400947. The reversal of 21404400937 is 73900440412.

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., 17198748736 + 4205652201 = 131144^2 + 64851^2 .

It is a cyclic number.

It is not a de Polignac number, because 21404400937 - 2¹¹ = 21404398889 is a prime.

It is not a weakly prime, because it can be changed into another prime (21404400947) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10702200468 + 10702200469.

It is an arithmetic number, because the mean of its divisors is an integer number (10702200469).

Almost surely, 2^21404400937 is an apocalyptic number.

It is an amenable number.

21404400937 is a deficient number, since it is larger than the sum of its proper divisors (1).

21404400937 is an equidigital number, since it uses as much as digits as its factorization.

21404400937 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24192, while the sum is 34.

The spelling of 21404400937 in words is "twenty-one billion, four hundred four million, four hundred thousand, nine hundred thirty-seven".