211439779458961 has 9 divisors (see below), whose sum is σ = 211852454796489. Its totient is φ = 211027906512036.

The previous prime is 211439779458913. The next prime is 211439779459019. The reversal of 211439779458961 is 169854977934112.

The square root of 211439779458961 is 14540969.

It is a perfect power (a square), and thus also a powerful number.

It is a de Polignac number, because none of the positive numbers 2^k-211439779458961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (211439779408961) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 7604912886 + ... + 7604940688.

Almost surely, 2^{211439779458961} is an apocalyptic number.

211439779458961 is the 14540969-th square number.

211439779458961 is the 7270485-th centered octagonal number.

It is an amenable number.

211439779458961 is a deficient number, since it is larger than the sum of its proper divisors (412675337528).

211439779458961 is an frugal number, since it uses more digits than its factorization.

211439779458961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56652 (or 28326 counting only the distinct ones).

The product of its digits is 823011840, while the sum is 76.

The spelling of 211439779458961 in words is "two hundred eleven trillion, four hundred thirty-nine billion, seven hundred seventy-nine million, four hundred fifty-eight thousand, nine hundred sixty-one".