20165506 has 4 divisors (see below), whose sum is σ = 30248262. Its totient is φ = 10082752.

The previous prime is 20165501. The next prime is 20165507. The reversal of 20165506 is 60556102.

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., 12924025 + 7241481 = 3595^2 + 2691^2 .

It is not an unprimeable number, because it can be changed into a prime (20165501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5041375 + ... + 5041378.

Almost surely, 2^20165506 is an apocalyptic number.

20165506 is a deficient number, since it is larger than the sum of its proper divisors (10082756).

20165506 is a wasteful number, since it uses less digits than its factorization.

20165506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10082755.

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 20165506 is about 4490.6019641024. The cubic root of 20165506 is about 272.1884597182.

The spelling of 20165506 in words is "twenty million, one hundred sixty-five thousand, five hundred six".