21413623 has 32 divisors (see below), whose sum is σ = 27998208. Its totient is φ = 15897600.

The previous prime is 21413617. The next prime is 21413641. The reversal of 21413623 is 32631412.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21413623 is a prime.

It is a super-2 number, since 2×21413623² = 917086499972258, which contains 22 as substring.

It is a plaindrome in base 13.

It is a junction number, because it is equal to n+sod(n) for n = 21413594 and 21413603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21413123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 220711 + ... + 220807.

It is an arithmetic number, because the mean of its divisors is an integer number (874944).

Almost surely, 2^21413623 is an apocalyptic number.

21413623 is a deficient number, since it is larger than the sum of its proper divisors (6584585).

21413623 is a wasteful number, since it uses less digits than its factorization.

21413623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223.

The product of its digits is 864, while the sum is 22.

The square root of 21413623 is about 4627.4856023547. The cubic root of 21413623 is about 277.6920100659.

The spelling of 21413623 in words is "twenty-one million, four hundred thirteen thousand, six hundred twenty-three".