20351399 has 4 divisors (see below), whose sum is σ = 20553000. Its totient is φ = 20149800.

The previous prime is 20351381. The next prime is 20351437. The reversal of 20351399 is 99315302.

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 20351399 - 2⁸ = 20351143 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20351339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 100649 + ... + 100850.

It is an arithmetic number, because the mean of its divisors is an integer number (5138250).

Almost surely, 2^20351399 is an apocalyptic number.

20351399 is a deficient number, since it is larger than the sum of its proper divisors (201601).

20351399 is a wasteful number, since it uses less digits than its factorization.

20351399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 201600.

The product of its (nonzero) digits is 7290, while the sum is 32.

The square root of 20351399 is about 4511.2524868378. The cubic root of 20351399 is about 273.0222803357.

The spelling of 20351399 in words is "twenty million, three hundred fifty-one thousand, three hundred ninety-nine".