20442440 has 16 divisors (see below), whose sum is σ = 45995580. Its totient is φ = 8176960.

The previous prime is 20442439. The next prime is 20442451. The reversal of 20442440 is 4424402.

It can be written as a sum of positive squares in 2 ways, for example, as 16370116 + 4072324 = 4046^2 + 2018^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 255491 + ... + 255570.

Almost surely, 2^20442440 is an apocalyptic number.

20442440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20442440 is an abundant number, since it is smaller than the sum of its proper divisors (25553140).

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

20442440 is a wasteful number, since it uses less digits than its factorization.

20442440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 511072 (or 511068 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 20.

The square root of 20442440 is about 4521.3316622429. The cubic root of 20442440 is about 273.4287920928.

Adding to 20442440 its reverse (4424402), we get a palindrome (24866842).

The spelling of 20442440 in words is "twenty million, four hundred forty-two thousand, four hundred forty".