21001283437 has 2 divisors, whose sum is σ = 21001283438. Its totient is φ = 21001283436.

The previous prime is 21001283431. The next prime is 21001283461. The reversal of 21001283437 is 73438210012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12791836201 + 8209447236 = 113101^2 + 90606^2 .

It is a cyclic number.

It is not a de Polignac number, because 21001283437 - 2⁷ = 21001283309 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21001283399 and 21001283408.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21001283431) 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, 10500641718 + 10500641719.

It is an arithmetic number, because the mean of its divisors is an integer number (10500641719).

Almost surely, 2^21001283437 is an apocalyptic number.

It is an amenable number.

21001283437 is a deficient number, since it is larger than the sum of its proper divisors (1).

21001283437 is an equidigital number, since it uses as much as digits as its factorization.

21001283437 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 31.

Adding to 21001283437 its reverse (73438210012), we get a palindrome (94439493449).

The spelling of 21001283437 in words is "twenty-one billion, one million, two hundred eighty-three thousand, four hundred thirty-seven".