20402500217 has 4 divisors (see below), whose sum is σ = 22257272976. Its totient is φ = 18547727460.

The previous prime is 20402500211. The next prime is 20402500229. The reversal of 20402500217 is 71200520402.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20402500217 - 2²⁰ = 20401451641 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20402500192 and 20402500201.

It is not an unprimeable number, because it can be changed into a prime (20402500211) 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, 927386363 + ... + 927386384.

It is an arithmetic number, because the mean of its divisors is an integer number (5564318244).

Almost surely, 2^20402500217 is an apocalyptic number.

It is an amenable number.

20402500217 is a deficient number, since it is larger than the sum of its proper divisors (1854772759).

20402500217 is a wasteful number, since it uses less digits than its factorization.

20402500217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1854772758.

The product of its (nonzero) digits is 1120, while the sum is 23.

The spelling of 20402500217 in words is "twenty billion, four hundred two million, five hundred thousand, two hundred seventeen".