20511434 has 4 divisors (see below), whose sum is σ = 30767154. Its totient is φ = 10255716.

The previous prime is 20511353. The next prime is 20511437. The reversal of 20511434 is 43411502.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 20025625 + 485809 = 4475^2 + 697^2 .

It is not an unprimeable number, because it can be changed into a prime (20511437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5127857 + ... + 5127860.

Almost surely, 2^20511434 is an apocalyptic number.

20511434 is a deficient number, since it is larger than the sum of its proper divisors (10255720).

20511434 is a wasteful number, since it uses less digits than its factorization.

20511434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10255719.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 20511434 is about 4528.9550671209. The cubic root of 20511434 is about 273.7360574761.

Adding to 20511434 its reverse (43411502), we get a palindrome (63922936).

The spelling of 20511434 in words is "twenty million, five hundred eleven thousand, four hundred thirty-four".