20402442 has 20 divisors (see below), whose sum is σ = 45716946. Its totient is φ = 6800760.

The previous prime is 20402441. The next prime is 20402443. The reversal of 20402442 is 24420402.

It is an interprime number because it is at equal distance from previous prime (20402441) and next prime (20402443).

It can be written as a sum of positive squares in only one way, i.e., 11634921 + 8767521 = 3411^2 + 2961^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (20402441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 62809 + ... + 63132.

Almost surely, 2^20402442 is an apocalyptic number.

20402442 is an abundant number, since it is smaller than the sum of its proper divisors (25314504).

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

20402442 is a wasteful number, since it uses less digits than its factorization.

20402442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125955 (or 125946 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 18.

The square root of 20402442 is about 4516.9062421086. The cubic root of 20402442 is about 273.2503439639.

Adding to 20402442 its reverse (24420402), we get a palindrome (44822844).

The spelling of 20402442 in words is "twenty million, four hundred two thousand, four hundred forty-two".