21023115 has 32 divisors (see below), whose sum is σ = 35942400. Its totient is φ = 10469760.

The previous prime is 21023113. The next prime is 21023117. The reversal of 21023115 is 51132012.

It is an interprime number because it is at equal distance from previous prime (21023113) and next prime (21023117).

It is not a de Polignac number, because 21023115 - 2¹ = 21023113 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a junction number, because it is equal to n+sod(n) for n = 21023094 and 21023103.

It is not an unprimeable number, because it can be changed into a prime (21023111) 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, 12706 + ... + 14264.

It is an arithmetic number, because the mean of its divisors is an integer number (1123200).

Almost surely, 2^21023115 is an apocalyptic number.

21023115 is a deficient number, since it is larger than the sum of its proper divisors (14919285).

21023115 is a wasteful number, since it uses less digits than its factorization.

21023115 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1627.

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 21023115 is about 4585.0970545889. The cubic root of 21023115 is about 275.9936067622.

Adding to 21023115 its reverse (51132012), we get a palindrome (72155127).

The spelling of 21023115 in words is "twenty-one million, twenty-three thousand, one hundred fifteen".