21962641 has 4 divisors (see below), whose sum is σ = 21973284. Its totient is φ = 21952000.

The previous prime is 21962621. The next prime is 21962659. The reversal of 21962641 is 14626912.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 9431041 + 12531600 = 3071^2 + 3540^2 .

It is a 3-Lehmer number, since φ(21962641) divides (21962641-1)³.

It is a cyclic number.

It is not a de Polignac number, because 21962641 - 2⁵ = 21962609 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21962621) 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, 1120 + ... + 6721.

It is an arithmetic number, because the mean of its divisors is an integer number (5493321).

Almost surely, 2^21962641 is an apocalyptic number.

It is an amenable number.

21962641 is a deficient number, since it is larger than the sum of its proper divisors (10643).

21962641 is an equidigital number, since it uses as much as digits as its factorization.

21962641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10642.

The product of its digits is 5184, while the sum is 31.

The square root of 21962641 is about 4686.4315849055. The cubic root of 21962641 is about 280.0452350387.

The spelling of 21962641 in words is "twenty-one million, nine hundred sixty-two thousand, six hundred forty-one".