20403139 has 4 divisors (see below), whose sum is σ = 21290256. Its totient is φ = 19516024.

The previous prime is 20403137. The next prime is 20403151. The reversal of 20403139 is 93130402.

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 20403139 - 2¹ = 20403137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20403133) 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, 443524 + ... + 443569.

It is an arithmetic number, because the mean of its divisors is an integer number (5322564).

Almost surely, 2^20403139 is an apocalyptic number.

20403139 is a deficient number, since it is larger than the sum of its proper divisors (887117).

20403139 is an equidigital number, since it uses as much as digits as its factorization.

20403139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 887116.

The product of its (nonzero) digits is 648, while the sum is 22.

The square root of 20403139 is about 4516.9833960288. The cubic root of 20403139 is about 273.2534555738.

The spelling of 20403139 in words is "twenty million, four hundred three thousand, one hundred thirty-nine".