20102440 has 32 divisors (see below), whose sum is σ = 45360000. Its totient is φ = 8017984.

The previous prime is 20102431. The next prime is 20102441. The reversal of 20102440 is 4420102.

It is a self number, because there is not a number n which added to its sum of digits gives 20102440.

It is not an unprimeable number, because it can be changed into a prime (20102441) 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, 23541 + ... + 24379.

It is an arithmetic number, because the mean of its divisors is an integer number (1417500).

Almost surely, 2^20102440 is an apocalyptic number.

20102440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20102440 is an abundant number, since it is smaller than the sum of its proper divisors (25257560).

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

20102440 is a wasteful number, since it uses less digits than its factorization.

20102440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1449 (or 1445 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 13.

The square root of 20102440 is about 4483.5744668735. The cubic root of 20102440 is about 271.9044142219.

Adding to 20102440 its reverse (4420102), we get a palindrome (24522542).

The spelling of 20102440 in words is "twenty million, one hundred two thousand, four hundred forty".