20400234 has 16 divisors (see below), whose sum is σ = 40848672. Its totient is φ = 6792048.

The previous prime is 20400197. The next prime is 20400239. The reversal of 20400234 is 43200402.

It is a happy number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20400239) 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, 5877 + ... + 8679.

It is an arithmetic number, because the mean of its divisors is an integer number (2553042).

Almost surely, 2^20400234 is an apocalyptic number.

20400234 is an abundant number, since it is smaller than the sum of its proper divisors (20448438).

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

20400234 is a wasteful number, since it uses less digits than its factorization.

20400234 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4021.

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

The square root of 20400234 is about 4516.6618204156. The cubic root of 20400234 is about 273.2404863445.

Adding to 20400234 its reverse (43200402), we get a palindrome (63600636).

The spelling of 20400234 in words is "twenty million, four hundred thousand, two hundred thirty-four".