212021181819 has 24 divisors (see below), whose sum is σ = 324806999712. Its totient is φ = 132985480320.

The previous prime is 212021181809. The next prime is 212021181829. The reversal of 212021181819 is 918181120212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (212021181809) and next prime (212021181829).

It is not a de Polignac number, because 212021181819 - 2¹³ = 212021173627 is a prime.

It is a super-2 number, since 2×212021181819² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (212021181809) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8382922 + ... + 8408175.

It is an arithmetic number, because the mean of its divisors is an integer number (13533624988).

Almost surely, 2^212021181819 is an apocalyptic number.

212021181819 is a deficient number, since it is larger than the sum of its proper divisors (112785817893).

212021181819 is a wasteful number, since it uses less digits than its factorization.

212021181819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16791187 (or 16791184 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 36.

It can be divided in two parts, 21202 and 1181819, that added together give a palindrome (1203021).

The spelling of 212021181819 in words is "two hundred twelve billion, twenty-one million, one hundred eighty-one thousand, eight hundred nineteen".