21140830 has 16 divisors (see below), whose sum is σ = 38982384. Its totient is φ = 8249920.

The previous prime is 21140827. The next prime is 21140837. The reversal of 21140830 is 3804112.

It is a junction number, because it is equal to n+sod(n) for n = 21140798 and 21140807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21140837) 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, 25372 + ... + 26191.

It is an arithmetic number, because the mean of its divisors is an integer number (2436399).

Almost surely, 2^21140830 is an apocalyptic number.

21140830 is a deficient number, since it is larger than the sum of its proper divisors (17841554).

21140830 is a wasteful number, since it uses less digits than its factorization.

21140830 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51611.

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 21140830 is about 4597.9158322005. The cubic root of 21140830 is about 276.5077731520.

Adding to 21140830 its reverse (3804112), we get a palindrome (24944942).

It can be divided in two parts, 211 and 40830, that added together give a triangular number (41041 = T₂₈₆).

The spelling of 21140830 in words is "twenty-one million, one hundred forty thousand, eight hundred thirty".