213611640 has 128 divisors (see below), whose sum is σ = 716325120. Its totient is φ = 50508800.

The previous prime is 213611639. The next prime is 213611653. The reversal of 213611640 is 46116312.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 213611640.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 52147 + ... + 56093.

It is an arithmetic number, because the mean of its divisors is an integer number (5596290).

Almost surely, 2^213611640 is an apocalyptic number.

213611640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 213611640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (358162560).

213611640 is an abundant number, since it is smaller than the sum of its proper divisors (502713480).

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

213611640 is a wasteful number, since it uses less digits than its factorization.

213611640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4013 (or 4009 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 213611640 is about 14615.4589390823. The cubic root of 213611640 is about 597.7803543029.

Adding to 213611640 its reverse (46116312), we get a palindrome (259727952).

The spelling of 213611640 in words is "two hundred thirteen million, six hundred eleven thousand, six hundred forty".