21623041 has 4 divisors (see below), whose sum is σ = 23588784. Its totient is φ = 19657300.

The previous prime is 21622999. The next prime is 21623057. The reversal of 21623041 is 14032612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21623041 - 2¹³ = 21614849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21623081) 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, 982855 + ... + 982876.

It is an arithmetic number, because the mean of its divisors is an integer number (5897196).

Almost surely, 2^21623041 is an apocalyptic number.

It is an amenable number.

21623041 is a deficient number, since it is larger than the sum of its proper divisors (1965743).

21623041 is a wasteful number, since it uses less digits than its factorization.

21623041 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1965742.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 21623041 is about 4650.0581716791. The cubic root of 21623041 is about 278.5943196868.

Adding to 21623041 its reverse (14032612), we get a palindrome (35655653).

The spelling of 21623041 in words is "twenty-one million, six hundred twenty-three thousand, forty-one".