21610140 has 24 divisors (see below), whose sum is σ = 60508560. Its totient is φ = 5762688.

The previous prime is 21610103. The next prime is 21610151. The reversal of 21610140 is 4101612.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a zygodrome in base 11.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 180025 + ... + 180144.

It is an arithmetic number, because the mean of its divisors is an integer number (2521190).

Almost surely, 2^21610140 is an apocalyptic number.

21610140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21610140 is an abundant number, since it is smaller than the sum of its proper divisors (38898420).

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

21610140 is a wasteful number, since it uses less digits than its factorization.

21610140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 360181 (or 360179 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 21610140 is about 4648.6707777600. The cubic root of 21610140 is about 278.5389025610.

Adding to 21610140 its reverse (4101612), we get a palindrome (25711752).

The spelling of 21610140 in words is "twenty-one million, six hundred ten thousand, one hundred forty".