21442641 has 8 divisors (see below), whose sum is σ = 31189344. Its totient is φ = 12995520.

The previous prime is 21442637. The next prime is 21442649. The reversal of 21442641 is 14624412.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21442641 - 2² = 21442637 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21442649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 324856 + ... + 324921.

It is an arithmetic number, because the mean of its divisors is an integer number (3898668).

Almost surely, 2^21442641 is an apocalyptic number.

It is an amenable number.

21442641 is a deficient number, since it is larger than the sum of its proper divisors (9746703).

21442641 is a wasteful number, since it uses less digits than its factorization.

21442641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 649791.

The product of its digits is 1536, while the sum is 24.

The square root of 21442641 is about 4630.6199368983. The cubic root of 21442641 is about 277.8173886564.

The spelling of 21442641 in words is "twenty-one million, four hundred forty-two thousand, six hundred forty-one".