21211511212 has 24 divisors (see below), whose sum is σ = 38648901312. Its totient is φ = 10177449600.

The previous prime is 21211511131. The next prime is 21211511239.

21211511212 is nontrivially palindromic in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 21211511212.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 1050148 + ... + 1070155.

It is an arithmetic number, because the mean of its divisors is an integer number (1610370888).

Almost surely, 2^21211511212 is an apocalyptic number.

It is an amenable number.

21211511212 is a deficient number, since it is larger than the sum of its proper divisors (17437390100).

21211511212 is a wasteful number, since it uses less digits than its factorization.

21211511212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2120409 (or 2120407 counting only the distinct ones).

The product of its digits is 80, while the sum is 19.

The spelling of 21211511212 in words is "twenty-one billion, two hundred eleven million, five hundred eleven thousand, two hundred twelve".