21611160 has 96 divisors (see below), whose sum is σ = 70845840. Its totient is φ = 5713152.

The previous prime is 21611159. The next prime is 21611167. The reversal of 21611160 is 6111612.

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 (21611167) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 62107 + ... + 62453.

Almost surely, 2^21611160 is an apocalyptic number.

21611160 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 21611160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35422920).

21611160 is an abundant number, since it is smaller than the sum of its proper divisors (49234680).

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

21611160 is a wasteful number, since it uses less digits than its factorization.

21611160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 537 (or 530 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 21611160 is about 4648.7804852456. The cubic root of 21611160 is about 278.5432848434.

Adding to 21611160 its reverse (6111612), we get a palindrome (27722772).

It can be divided in two parts, 2161 and 1160, that added together give a triangular number (3321 = T₈₁).

The spelling of 21611160 in words is "twenty-one million, six hundred eleven thousand, one hundred sixty".