21700160 has 56 divisors (see below), whose sum is σ = 54726840. Its totient is φ = 8167424.

The previous prime is 21700127. The next prime is 21700169. The reversal of 21700160 is 6100712.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 4194304 + 17505856 = 2048^2 + 4184^2 .

It is a Harshad number since it is a multiple of its sum of digits (17).

It is not an unprimeable number, because it can be changed into a prime (21700169) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3446 + ... + 7434.

It is an arithmetic number, because the mean of its divisors is an integer number (977265).

Almost surely, 2^21700160 is an apocalyptic number.

21700160 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 21700160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27363420).

21700160 is an abundant number, since it is smaller than the sum of its proper divisors (33026680).

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

21700160 is a wasteful number, since it uses less digits than its factorization.

21700160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4023 (or 4013 counting only the distinct ones).

The product of its (nonzero) digits is 84, while the sum is 17.

The square root of 21700160 is about 4658.3430530608. The cubic root of 21700160 is about 278.9251307524.

Adding to 21700160 its reverse (6100712), we get a palindrome (27800872).

The spelling of 21700160 in words is "twenty-one million, seven hundred thousand, one hundred sixty".