13211640 has 128 divisors (see below), whose sum is σ = 47476800. Its totient is φ = 3248640.

The previous prime is 13211623. The next prime is 13211641. The reversal of 13211640 is 4611231.

It is a happy number.

13211640 is a `hidden beast` number, since 1 + 3 + 21 + 1 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13211641) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13570 + ... + 14510.

Almost surely, 2^13211640 is an apocalyptic number.

13211640 is a gapful number since it is divisible by the number (10) 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 13211640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23738400).

13211640 is an abundant number, since it is smaller than the sum of its proper divisors (34265160).

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

13211640 is a wasteful number, since it uses less digits than its factorization.

13211640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 974 (or 964 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 13211640 is about 3634.7819742042. The cubic root of 13211640 is about 236.4025973071.

Adding to 13211640 its reverse (4611231), we get a palindrome (17822871).

The spelling of 13211640 in words is "thirteen million, two hundred eleven thousand, six hundred forty".