21220770237 has 4 divisors (see below), whose sum is σ = 28294360320. Its totient is φ = 14147180156.

The previous prime is 21220770227. The next prime is 21220770257. The reversal of 21220770237 is 73207702212.

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 a cyclic number.

It is not a de Polignac number, because 21220770237 - 2²⁴ = 21203993021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21220770198 and 21220770207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220770227) 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, 3536795037 + ... + 3536795042.

It is an arithmetic number, because the mean of its divisors is an integer number (7073590080).

Almost surely, 2^21220770237 is an apocalyptic number.

It is an amenable number.

21220770237 is a deficient number, since it is larger than the sum of its proper divisors (7073590083).

21220770237 is an equidigital number, since it uses as much as digits as its factorization.

21220770237 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7073590082.

The product of its (nonzero) digits is 16464, while the sum is 33.

The spelling of 21220770237 in words is "twenty-one billion, two hundred twenty million, seven hundred seventy thousand, two hundred thirty-seven".