21630012137 has 6 divisors (see below), whose sum is σ = 22350263274. Its totient is φ = 20932268880.

The previous prime is 21630012127. The next prime is 21630012149. The reversal of 21630012137 is 73121003612.

It can be written as a sum of positive squares in only one way, i.e., 18301760656 + 3328251481 = 135284^2 + 57691^2 .

It is not a de Polignac number, because 21630012137 - 2⁸ = 21630011881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21630012127) 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 in 5 ways as a sum of consecutive naturals, for example, 11252948 + ... + 11254869.

It is an arithmetic number, because the mean of its divisors is an integer number (3725043879).

Almost surely, 2^21630012137 is an apocalyptic number.

It is an amenable number.

21630012137 is a deficient number, since it is larger than the sum of its proper divisors (720251137).

21630012137 is an equidigital number, since it uses as much as digits as its factorization.

21630012137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22507879 (or 22507848 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 26.

Adding to 21630012137 its reverse (73121003612), we get a palindrome (94751015749).

The spelling of 21630012137 in words is "twenty-one billion, six hundred thirty million, twelve thousand, one hundred thirty-seven".