20209151 has 4 divisors (see below), whose sum is σ = 20222400. Its totient is φ = 20195904.

The previous prime is 20209139. The next prime is 20209153. The reversal of 20209151 is 15190202.

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

It is a cyclic number.

It is not a de Polignac number, because 20209151 - 2⁶ = 20209087 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20209153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3986 + ... + 7503.

It is an arithmetic number, because the mean of its divisors is an integer number (5055600).

Almost surely, 2^20209151 is an apocalyptic number.

20209151 is a deficient number, since it is larger than the sum of its proper divisors (13249).

20209151 is a wasteful number, since it uses less digits than its factorization.

20209151 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13248.

The product of its (nonzero) digits is 180, while the sum is 20.

The square root of 20209151 is about 4495.4589309658. The cubic root of 20209151 is about 272.3846876246.

Adding to 20209151 its reverse (15190202), we get a palindrome (35399353).

The spelling of 20209151 in words is "twenty million, two hundred nine thousand, one hundred fifty-one".