20634641 has 4 divisors (see below), whose sum is σ = 21192372. Its totient is φ = 20076912.

The previous prime is 20634619. The next prime is 20634643. The reversal of 20634641 is 14643602.

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 14409616 + 6225025 = 3796^2 + 2495^2 .

It is a cyclic number.

It is not a de Polignac number, because 20634641 - 2¹⁰ = 20633617 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 20634641.

It is not an unprimeable number, because it can be changed into a prime (20634643) 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, 278810 + ... + 278883.

It is an arithmetic number, because the mean of its divisors is an integer number (5298093).

Almost surely, 2^20634641 is an apocalyptic number.

It is an amenable number.

20634641 is a deficient number, since it is larger than the sum of its proper divisors (557731).

20634641 is an equidigital number, since it uses as much as digits as its factorization.

20634641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 557730.

The product of its (nonzero) digits is 3456, while the sum is 26.

The square root of 20634641 is about 4542.5368463008. The cubic root of 20634641 is about 274.2830514865.

The spelling of 20634641 in words is "twenty million, six hundred thirty-four thousand, six hundred forty-one".