21020636941 has 4 divisors (see below), whose sum is σ = 21073057884. Its totient is φ = 20968216000.

The previous prime is 21020636893. The next prime is 21020636993. The reversal of 21020636941 is 14963602012.

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 12213565225 + 8807071716 = 110515^2 + 93846^2 .

It is a cyclic number.

It is not a de Polignac number, because 21020636941 - 2¹¹ = 21020634893 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21020636897 and 21020636906.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020636041) 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, 26209870 + ... + 26210671.

It is an arithmetic number, because the mean of its divisors is an integer number (5268264471).

Almost surely, 2^21020636941 is an apocalyptic number.

It is an amenable number.

21020636941 is a deficient number, since it is larger than the sum of its proper divisors (52420943).

21020636941 is an equidigital number, since it uses as much as digits as its factorization.

21020636941 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52420942.

The product of its (nonzero) digits is 15552, while the sum is 34.

The spelling of 21020636941 in words is "twenty-one billion, twenty million, six hundred thirty-six thousand, nine hundred forty-one".