21623103 has 6 divisors (see below), whose sum is σ = 31233384. Its totient is φ = 14415396.

The previous prime is 21623101. The next prime is 21623131. The reversal of 21623103 is 30132612.

It is not a de Polignac number, because 21623103 - 2¹ = 21623101 is a prime.

It is a super-4 number, since 4×21623103⁴ (a number of 30 digits) contains 4444 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21623101) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1201275 + ... + 1201292.

It is an arithmetic number, because the mean of its divisors is an integer number (5205564).

Almost surely, 2^21623103 is an apocalyptic number.

21623103 is a deficient number, since it is larger than the sum of its proper divisors (9610281).

21623103 is a wasteful number, since it uses less digits than its factorization.

21623103 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2402573 (or 2402570 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

The square root of 21623103 is about 4650.0648382576. The cubic root of 21623103 is about 278.5945859588.

Adding to 21623103 its reverse (30132612), we get a palindrome (51755715).

The spelling of 21623103 in words is "twenty-one million, six hundred twenty-three thousand, one hundred three".