20260640 has 48 divisors (see below), whose sum is σ = 48263040. Its totient is φ = 8037120.

The previous prime is 20260637. The next prime is 20260649. The reversal of 20260640 is 4606202.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (20260649) 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, 21785 + ... + 22695.

It is an arithmetic number, because the mean of its divisors is an integer number (1005480).

Almost surely, 2^20260640 is an apocalyptic number.

20260640 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 20260640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24131520).

20260640 is an abundant number, since it is smaller than the sum of its proper divisors (28002400).

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

20260640 is a wasteful number, since it uses less digits than its factorization.

20260640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1065 (or 1057 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 20260640 is about 4501.1820669686. The cubic root of 20260640 is about 272.6158192405.

Adding to 20260640 its reverse (4606202), we get a palindrome (24866842).

The spelling of 20260640 in words is "twenty million, two hundred sixty thousand, six hundred forty".