20355506403 has 4 divisors (see below), whose sum is σ = 27140675208. Its totient is φ = 13570337600.

The previous prime is 20355506387. The next prime is 20355506411. The reversal of 20355506403 is 30460555302.

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 20355506403 - 2⁴ = 20355506387 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20355506473) 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, 3392584398 + ... + 3392584403.

It is an arithmetic number, because the mean of its divisors is an integer number (6785168802).

Almost surely, 2^20355506403 is an apocalyptic number.

20355506403 is a deficient number, since it is larger than the sum of its proper divisors (6785168805).

20355506403 is an equidigital number, since it uses as much as digits as its factorization.

20355506403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6785168804.

The product of its (nonzero) digits is 54000, while the sum is 33.

The spelling of 20355506403 in words is "twenty billion, three hundred fifty-five million, five hundred six thousand, four hundred three".