20636200621 has 4 divisors (see below), whose sum is σ = 21301884544. Its totient is φ = 19970516700.

The previous prime is 20636200603. The next prime is 20636200639. The reversal of 20636200621 is 12600263602.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12600263602 = 2 ⋅6300131801.

It is an interprime number because it is at equal distance from previous prime (20636200603) and next prime (20636200639).

It is a cyclic number.

It is not a de Polignac number, because 20636200621 - 2¹⁷ = 20636069549 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20636200621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20636204621) 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, 332841915 + ... + 332841976.

It is an arithmetic number, because the mean of its divisors is an integer number (5325471136).

Almost surely, 2^20636200621 is an apocalyptic number.

It is an amenable number.

20636200621 is a deficient number, since it is larger than the sum of its proper divisors (665683923).

20636200621 is an equidigital number, since it uses as much as digits as its factorization.

20636200621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 665683922.

The product of its (nonzero) digits is 5184, while the sum is 28.

The spelling of 20636200621 in words is "twenty billion, six hundred thirty-six million, two hundred thousand, six hundred twenty-one".