21300137 has 2 divisors, whose sum is σ = 21300138. Its totient is φ = 21300136.

The previous prime is 21300127. The next prime is 21300143. The reversal of 21300137 is 73100312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11162281 + 10137856 = 3341^2 + 3184^2 .

It is a cyclic number.

It is not a de Polignac number, because 21300137 - 2¹⁶ = 21234601 is a prime.

It is not a weakly prime, because it can be changed into another prime (21300127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10650068 + 10650069.

It is an arithmetic number, because the mean of its divisors is an integer number (10650069).

Almost surely, 2^21300137 is an apocalyptic number.

It is an amenable number.

21300137 is a deficient number, since it is larger than the sum of its proper divisors (1).

21300137 is an equidigital number, since it uses as much as digits as its factorization.

21300137 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 126, while the sum is 17.

The square root of 21300137 is about 4615.2071459470. The cubic root of 21300137 is about 277.2005784834.

Adding to 21300137 its reverse (73100312), we get a palindrome (94400449).

The spelling of 21300137 in words is "twenty-one million, three hundred thousand, one hundred thirty-seven".