21115430 has 16 divisors (see below), whose sum is σ = 43437600. Its totient is φ = 7239552.

The previous prime is 21115429. The next prime is 21115439. The reversal of 21115430 is 3451112.

It is a super-2 number, since 2×21115430² = 891722768169800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21115399 and 21115408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21115439) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 150755 + ... + 150894.

It is an arithmetic number, because the mean of its divisors is an integer number (2714850).

Almost surely, 2^21115430 is an apocalyptic number.

21115430 is an abundant number, since it is smaller than the sum of its proper divisors (22322170).

21115430 is a wasteful number, since it uses less digits than its factorization.

21115430 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 301663.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 21115430 is about 4595.1528810258. The cubic root of 21115430 is about 276.3969904932.

Adding to 21115430 its reverse (3451112), we get a palindrome (24566542).

The spelling of 21115430 in words is "twenty-one million, one hundred fifteen thousand, four hundred thirty".