21154670 has 16 divisors (see below), whose sum is σ = 38601360. Its totient is φ = 8345664.

The previous prime is 21154669. The next prime is 21154673. The reversal of 21154670 is 7645112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21154673) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 13760 + ... + 15219.

It is an arithmetic number, because the mean of its divisors is an integer number (2412585).

Almost surely, 2^21154670 is an apocalyptic number.

21154670 is a deficient number, since it is larger than the sum of its proper divisors (17446690).

21154670 is a wasteful number, since it uses less digits than its factorization.

21154670 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29059.

The product of its (nonzero) digits is 1680, while the sum is 26.

The square root of 21154670 is about 4599.4206156863. The cubic root of 21154670 is about 276.5680992727.

Adding to 21154670 its reverse (7645112), we get a palindrome (28799782).

The spelling of 21154670 in words is "twenty-one million, one hundred fifty-four thousand, six hundred seventy".