21211219972 has 12 divisors (see below), whose sum is σ = 37121481180. Its totient is φ = 10605082496.

The previous prime is 21211219963. The next prime is 21211219973. The reversal of 21211219972 is 27991211212.

It can be written as a sum of positive squares in 2 ways, for example, as 17301719296 + 3909500676 = 131536^2 + 62526^2 .

It is not an unprimeable number, because it can be changed into a prime (21211219973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33193 + ... + 208624.

It is an arithmetic number, because the mean of its divisors is an integer number (3093456765).

Almost surely, 2^21211219972 is an apocalyptic number.

It is an amenable number.

21211219972 is a deficient number, since it is larger than the sum of its proper divisors (15910261208).

21211219972 is a wasteful number, since it uses less digits than its factorization.

21211219972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263750 (or 263748 counting only the distinct ones).

The product of its digits is 9072, while the sum is 37.

The spelling of 21211219972 in words is "twenty-one billion, two hundred eleven million, two hundred nineteen thousand, nine hundred seventy-two".