20400434 has 8 divisors (see below), whose sum is σ = 31020060. Its totient is φ = 10060416.

The previous prime is 20400421. The next prime is 20400437. The reversal of 20400434 is 43400402.

It can be written as a sum of positive squares in 2 ways, for example, as 19492225 + 908209 = 4415^2 + 953^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (20400437) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 69719 + ... + 70010.

Almost surely, 2^20400434 is an apocalyptic number.

20400434 is a deficient number, since it is larger than the sum of its proper divisors (10619626).

20400434 is a wasteful number, since it uses less digits than its factorization.

20400434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139804.

The product of its (nonzero) digits is 384, while the sum is 17.

The square root of 20400434 is about 4516.6839606065. The cubic root of 20400434 is about 273.2413792741.

Adding to 20400434 its reverse (43400402), we get a palindrome (63800836).

The spelling of 20400434 in words is "twenty million, four hundred thousand, four hundred thirty-four".