21237221037 has 4 divisors (see below), whose sum is σ = 28316294720. Its totient is φ = 14158147356.

The previous prime is 21237220997. The next prime is 21237221081. The reversal of 21237221037 is 73012273212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21237221037 - 2⁷ = 21237220909 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21237220995 and 21237221013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21237221437) 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 3 ways as a sum of consecutive naturals, for example, 3539536837 + ... + 3539536842.

It is an arithmetic number, because the mean of its divisors is an integer number (7079073680).

Almost surely, 2^21237221037 is an apocalyptic number.

It is an amenable number.

21237221037 is a deficient number, since it is larger than the sum of its proper divisors (7079073683).

21237221037 is an equidigital number, since it uses as much as digits as its factorization.

21237221037 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7079073682.

The product of its (nonzero) digits is 7056, while the sum is 30.

Adding to 21237221037 its reverse (73012273212), we get a palindrome (94249494249).

The spelling of 21237221037 in words is "twenty-one billion, two hundred thirty-seven million, two hundred twenty-one thousand, thirty-seven".