20511242 has 4 divisors (see below), whose sum is σ = 30766866. Its totient is φ = 10255620.

The previous prime is 20511221. The next prime is 20511251. The reversal of 20511242 is 24211502.

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., 16394401 + 4116841 = 4049^2 + 2029^2 .

It is a super-2 number, since 2×20511242² = 841422096765128, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20511242.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5127809 + ... + 5127812.

Almost surely, 2^20511242 is an apocalyptic number.

20511242 is a deficient number, since it is larger than the sum of its proper divisors (10255624).

20511242 is a wasteful number, since it uses less digits than its factorization.

20511242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10255623.

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 20511242 is about 4528.9338701288. The cubic root of 20511242 is about 273.7352033592.

Adding to 20511242 its reverse (24211502), we get a palindrome (44722744).

The spelling of 20511242 in words is "twenty million, five hundred eleven thousand, two hundred forty-two".