20621112109 has 4 divisors (see below), whose sum is σ = 22207351516. Its totient is φ = 19034872704.

The previous prime is 20621112107. The next prime is 20621112143. The reversal of 20621112109 is 90121112602.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4750655625 + 15870456484 = 68925^2 + 125978^2 .

It is a cyclic number.

It is not a de Polignac number, because 20621112109 - 2¹ = 20621112107 is a prime.

It is a super-2 number, since 2×20621112109² (a number of 21 digits) contains 22 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 (20621112107) 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, 793119684 + ... + 793119709.

It is an arithmetic number, because the mean of its divisors is an integer number (5551837879).

Almost surely, 2^20621112109 is an apocalyptic number.

It is an amenable number.

20621112109 is a deficient number, since it is larger than the sum of its proper divisors (1586239407).

20621112109 is a wasteful number, since it uses less digits than its factorization.

20621112109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1586239406.

The product of its (nonzero) digits is 432, while the sum is 25.

The spelling of 20621112109 in words is "twenty billion, six hundred twenty-one million, one hundred twelve thousand, one hundred nine".