20635140 has 96 divisors (see below), whose sum is σ = 63544320. Its totient is φ = 4980096.

The previous prime is 20635103. The next prime is 20635169. The reversal of 20635140 is 4153602.

It is a happy number.

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, 25827 + ... + 26613.

It is an arithmetic number, because the mean of its divisors is an integer number (661920).

Almost surely, 2^20635140 is an apocalyptic number.

20635140 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 20635140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31772160).

20635140 is an abundant number, since it is smaller than the sum of its proper divisors (42909180).

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

20635140 is a wasteful number, since it uses less digits than its factorization.

20635140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 841 (or 839 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 20635140 is about 4542.5917712249. The cubic root of 20635140 is about 274.2852624311.

Adding to 20635140 its reverse (4153602), we get a palindrome (24788742).

The spelling of 20635140 in words is "twenty million, six hundred thirty-five thousand, one hundred forty".