20506211437 has 4 divisors (see below), whose sum is σ = 20942513856. Its totient is φ = 20069909020.

The previous prime is 20506211417. The next prime is 20506211449. The reversal of 20506211437 is 73411260502.

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, and also an emirpimes, since its reverse is a distinct semiprime: 73411260502 = 2 ⋅36705630251.

It is a cyclic number.

It is not a de Polignac number, because 20506211437 - 2¹⁵ = 20506178669 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20506211399 and 20506211408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20506211417) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 218151139 + ... + 218151232.

It is an arithmetic number, because the mean of its divisors is an integer number (5235628464).

Almost surely, 2^20506211437 is an apocalyptic number.

It is an amenable number.

20506211437 is a deficient number, since it is larger than the sum of its proper divisors (436302419).

20506211437 is an equidigital number, since it uses as much as digits as its factorization.

20506211437 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 436302418.

The product of its (nonzero) digits is 10080, while the sum is 31.

Adding to 20506211437 its reverse (73411260502), we get a palindrome (93917471939).

The spelling of 20506211437 in words is "twenty billion, five hundred six million, two hundred eleven thousand, four hundred thirty-seven".