21918152213 has 4 divisors (see below), whose sum is σ = 21919754400. Its totient is φ = 21916550028.

The previous prime is 21918152203. The next prime is 21918152227. The reversal of 21918152213 is 31225181912.

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 21918152213 - 2¹⁸ = 21917890069 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21918152203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 780395 + ... + 807992.

It is an arithmetic number, because the mean of its divisors is an integer number (5479938600).

Almost surely, 2^21918152213 is an apocalyptic number.

It is an amenable number.

21918152213 is a deficient number, since it is larger than the sum of its proper divisors (1602187).

21918152213 is a wasteful number, since it uses less digits than its factorization.

21918152213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1602186.

The product of its digits is 8640, while the sum is 35.

The spelling of 21918152213 in words is "twenty-one billion, nine hundred eighteen million, one hundred fifty-two thousand, two hundred thirteen".