211720661512 has 16 divisors (see below), whose sum is σ = 397510539840. Its totient is φ = 105717850896.

The previous prime is 211720661507. The next prime is 211720661531. The reversal of 211720661512 is 215166027112.

It is a super-2 number, since 2×211720661512² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17803668 + ... + 17815555.

It is an arithmetic number, because the mean of its divisors is an integer number (24844408740).

Almost surely, 2^211720661512 is an apocalyptic number.

It is an amenable number.

211720661512 is a deficient number, since it is larger than the sum of its proper divisors (185789878328).

211720661512 is a wasteful number, since it uses less digits than its factorization.

211720661512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35619972 (or 35619968 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 34.

Adding to 211720661512 its reverse (215166027112), we get a palindrome (426886688624).

The spelling of 211720661512 in words is "two hundred eleven billion, seven hundred twenty million, six hundred sixty-one thousand, five hundred twelve".