21166354 has 16 divisors (see below), whose sum is σ = 34727616. Its totient is φ = 9595600.

The previous prime is 21166337. The next prime is 21166357. The reversal of 21166354 is 45366112.

It is not an unprimeable number, because it can be changed into a prime (21166357) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9099 + ... + 11185.

It is an arithmetic number, because the mean of its divisors is an integer number (2170476).

Almost surely, 2^21166354 is an apocalyptic number.

21166354 is a deficient number, since it is larger than the sum of its proper divisors (13561262).

21166354 is a wasteful number, since it uses less digits than its factorization.

21166354 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2561.

The product of its digits is 4320, while the sum is 28.

The square root of 21166354 is about 4600.6906003338. The cubic root of 21166354 is about 276.6190072903.

It can be divided in two parts, 21 and 166354, that added together give a cube (166375 = 55³).

The spelling of 21166354 in words is "twenty-one million, one hundred sixty-six thousand, three hundred fifty-four".