20120399 has 4 divisors (see below), whose sum is σ = 21668136. Its totient is φ = 18572664.

The previous prime is 20120383. The next prime is 20120407. The reversal of 20120399 is 99302102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99302102 = 2 ⋅49651051.

It is a cyclic number.

It is not a de Polignac number, because 20120399 - 2⁴ = 20120383 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 (20120899) 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, 773849 + ... + 773874.

It is an arithmetic number, because the mean of its divisors is an integer number (5417034).

Almost surely, 2^20120399 is an apocalyptic number.

20120399 is a deficient number, since it is larger than the sum of its proper divisors (1547737).

20120399 is a wasteful number, since it uses less digits than its factorization.

20120399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1547736.

The product of its (nonzero) digits is 972, while the sum is 26.

The square root of 20120399 is about 4485.5767745074. The cubic root of 20120399 is about 271.9853609120.

The spelling of 20120399 in words is "twenty million, one hundred twenty thousand, three hundred ninety-nine".