20425999 has 4 divisors (see below), whose sum is σ = 22282920. Its totient is φ = 18569080.

The previous prime is 20425987. The next prime is 20426009. The reversal of 20425999 is 99952402.

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 20425999 - 2⁵ = 20425967 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20425939) 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, 928444 + ... + 928465.

It is an arithmetic number, because the mean of its divisors is an integer number (5570730).

Almost surely, 2^20425999 is an apocalyptic number.

20425999 is a deficient number, since it is larger than the sum of its proper divisors (1856921).

20425999 is a wasteful number, since it uses less digits than its factorization.

20425999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1856920.

The product of its (nonzero) digits is 58320, while the sum is 40.

The square root of 20425999 is about 4519.5131374961. The cubic root of 20425999 is about 273.3554699832.

The spelling of 20425999 in words is "twenty million, four hundred twenty-five thousand, nine hundred ninety-nine".