21012941 has 4 divisors (see below), whose sum is σ = 21073500. Its totient is φ = 20952384.

The previous prime is 21012913. The next prime is 21012991. The reversal of 21012941 is 14921012.

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 5244100 + 15768841 = 2290^2 + 3971^2 .

It is a cyclic number.

It is not a de Polignac number, because 21012941 - 2⁶ = 21012877 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012991) 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, 29756 + ... + 30453.

It is an arithmetic number, because the mean of its divisors is an integer number (5268375).

Almost surely, 2^21012941 is an apocalyptic number.

It is an amenable number.

21012941 is a deficient number, since it is larger than the sum of its proper divisors (60559).

21012941 is an equidigital number, since it uses as much as digits as its factorization.

21012941 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60558.

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 21012941 is about 4583.9874563528. The cubic root of 21012941 is about 275.9490778070.

Adding to 21012941 its reverse (14921012), we get a palindrome (35933953).

The spelling of 21012941 in words is "twenty-one million, twelve thousand, nine hundred forty-one".