20011221238 has 4 divisors (see below), whose sum is σ = 30016831860. Its totient is φ = 10005610618.

The previous prime is 20011221193. The next prime is 20011221239. The reversal of 20011221238 is 83212211002.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20011221239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5002805308 + ... + 5002805311.

It is an arithmetic number, because the mean of its divisors is an integer number (7504207965).

Almost surely, 2^20011221238 is an apocalyptic number.

20011221238 is a deficient number, since it is larger than the sum of its proper divisors (10005610622).

20011221238 is a wasteful number, since it uses less digits than its factorization.

20011221238 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10005610621.

The product of its (nonzero) digits is 384, while the sum is 22.

The spelling of 20011221238 in words is "twenty billion, eleven million, two hundred twenty-one thousand, two hundred thirty-eight".