20650645621 has 4 divisors (see below), whose sum is σ = 20659431744. Its totient is φ = 20641859500.

The previous prime is 20650645607. The next prime is 20650645627. The reversal of 20650645621 is 12654605602.

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 20650645621 - 2⁷ = 20650645493 is a prime.

It is a super-3 number, since 3×20650645621³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20650645627) 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, 4389535 + ... + 4394236.

It is an arithmetic number, because the mean of its divisors is an integer number (5164857936).

Almost surely, 2^20650645621 is an apocalyptic number.

It is an amenable number.

20650645621 is a deficient number, since it is larger than the sum of its proper divisors (8786123).

20650645621 is an equidigital number, since it uses as much as digits as its factorization.

20650645621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8786122.

The product of its (nonzero) digits is 86400, while the sum is 37.

The spelling of 20650645621 in words is "twenty billion, six hundred fifty million, six hundred forty-five thousand, six hundred twenty-one".