21026115 has 32 divisors (see below), whose sum is σ = 40780800. Its totient is φ = 10193760.

The previous prime is 21026099. The next prime is 21026119. The reversal of 21026115 is 51162012.

It is not a de Polignac number, because 21026115 - 2⁴ = 21026099 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21026119) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5595 + ... + 8564.

It is an arithmetic number, because the mean of its divisors is an integer number (1274400).

Almost surely, 2^21026115 is an apocalyptic number.

21026115 is a deficient number, since it is larger than the sum of its proper divisors (19754685).

21026115 is a wasteful number, since it uses less digits than its factorization.

21026115 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14184 (or 14178 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 21026115 is about 4585.4241897561. The cubic root of 21026115 is about 276.0067342402.

Adding to 21026115 its reverse (51162012), we get a palindrome (72188127).

It can be divided in two parts, 210261 and 15, that added together give a triangular number (210276 = T₆₄₈).

The spelling of 21026115 in words is "twenty-one million, twenty-six thousand, one hundred fifteen".