21623115 has 16 divisors (see below), whose sum is σ = 34905888. Its totient is φ = 11429376.

The previous prime is 21623101. The next prime is 21623131. The reversal of 21623115 is 51132612.

It is not a de Polignac number, because 21623115 - 2⁷ = 21622987 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21623091 and 21623100.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4684 + ... + 8073.

It is an arithmetic number, because the mean of its divisors is an integer number (2181618).

Almost surely, 2^21623115 is an apocalyptic number.

21623115 is a deficient number, since it is larger than the sum of its proper divisors (13282773).

21623115 is a wasteful number, since it uses less digits than its factorization.

21623115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12878.

The product of its digits is 360, while the sum is 21.

The square root of 21623115 is about 4650.0661285620. The cubic root of 21623115 is about 278.5946374953.

Adding to 21623115 its reverse (51132612), we get a palindrome (72755727).

The spelling of 21623115 in words is "twenty-one million, six hundred twenty-three thousand, one hundred fifteen".