20351869 has 4 divisors (see below), whose sum is σ = 21423040. Its totient is φ = 19280700.

The previous prime is 20351843. The next prime is 20351899. The reversal of 20351869 is 96815302.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 96815302 = 2 ⋅48407651.

It is a cyclic number.

It is not a de Polignac number, because 20351869 - 2⁷ = 20351741 is a prime.

It is a super-2 number, since 2×20351869² = 828397143586322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20351809) 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, 535557 + ... + 535594.

It is an arithmetic number, because the mean of its divisors is an integer number (5355760).

Almost surely, 2^20351869 is an apocalyptic number.

It is an amenable number.

20351869 is a deficient number, since it is larger than the sum of its proper divisors (1071171).

20351869 is a wasteful number, since it uses less digits than its factorization.

20351869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1071170.

The product of its (nonzero) digits is 12960, while the sum is 34.

The square root of 20351869 is about 4511.3045785005. The cubic root of 20351869 is about 273.0243820665.

The spelling of 20351869 in words is "twenty million, three hundred fifty-one thousand, eight hundred sixty-nine".