211620165006555 has 48 divisors (see below), whose sum is σ = 370933377048000. Its totient is φ = 111594854181888.

The previous prime is 211620165006493. The next prime is 211620165006559. The reversal of 211620165006555 is 555600561026112.

It is a happy number.

211620165006555 is a `hidden beast` number, since 2 + 1 + 1 + 6 + 20 + 16 + 500 + 65 + 55 = 666.

211620165006555 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 211620165006555 - 2²¹ = 211620162909403 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 211620165006555.

It is not an unprimeable number, because it can be changed into a prime (211620165006559) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 554778186 + ... + 555159504.

It is an arithmetic number, because the mean of its divisors is an integer number (7727778688500).

Almost surely, 2^{211620165006555} is an apocalyptic number.

211620165006555 is a deficient number, since it is larger than the sum of its proper divisors (159313212041445).

211620165006555 is a wasteful number, since it uses less digits than its factorization.

211620165006555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 519988 (or 519985 counting only the distinct ones).

The product of its (nonzero) digits is 540000, while the sum is 45.

The spelling of 211620165006555 in words is "two hundred eleven trillion, six hundred twenty billion, one hundred sixty-five million, six thousand, five hundred fifty-five".