213111660 has 48 divisors (see below), whose sum is σ = 631816416. Its totient is φ = 53486592.

The previous prime is 213111653. The next prime is 213111667. The reversal of 213111660 is 66111312.

It is an interprime number because it is at equal distance from previous prime (213111653) and next prime (213111667).

It is not an unprimeable number, because it can be changed into a prime (213111667) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 103447 + ... + 105486.

It is an arithmetic number, because the mean of its divisors is an integer number (13162842).

Almost surely, 2^213111660 is an apocalyptic number.

213111660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

213111660 is an abundant number, since it is smaller than the sum of its proper divisors (418704756).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

213111660 is a wasteful number, since it uses less digits than its factorization.

213111660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208962 (or 208960 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 21.

The square root of 213111660 is about 14598.3444266807. The cubic root of 213111660 is about 597.3136011642.

Adding to 213111660 its reverse (66111312), we get a palindrome (279222972).

The spelling of 213111660 in words is "two hundred thirteen million, one hundred eleven thousand, six hundred sixty".