20400342 has 16 divisors (see below), whose sum is σ = 41163120. Its totient is φ = 6739712.

The previous prime is 20400337. The next prime is 20400349. The reversal of 20400342 is 24300402.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20400349) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14367 + ... + 15722.

It is an arithmetic number, because the mean of its divisors is an integer number (2572695).

Almost surely, 2^20400342 is an apocalyptic number.

20400342 is an abundant number, since it is smaller than the sum of its proper divisors (20762778).

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

20400342 is a wasteful number, since it uses less digits than its factorization.

20400342 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30207.

The product of its (nonzero) digits is 192, while the sum is 15.

The square root of 20400342 is about 4516.6737761322. The cubic root of 20400342 is about 273.2409685272.

Adding to 20400342 its reverse (24300402), we get a palindrome (44700744).

The spelling of 20400342 in words is "twenty million, four hundred thousand, three hundred forty-two".