21708154 has 16 divisors (see below), whose sum is σ = 35152992. Its totient is φ = 9994608.

The previous prime is 21708151. The next prime is 21708157. The reversal of 21708154 is 45180712.

It is an interprime number because it is at equal distance from previous prime (21708151) and next prime (21708157).

It is not an unprimeable number, because it can be changed into a prime (21708151) 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, 13897 + ... + 15379.

It is an arithmetic number, because the mean of its divisors is an integer number (2197062).

Almost surely, 2^21708154 is an apocalyptic number.

21708154 is a deficient number, since it is larger than the sum of its proper divisors (13444838).

21708154 is a wasteful number, since it uses less digits than its factorization.

21708154 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2061.

The product of its (nonzero) digits is 2240, while the sum is 28.

The square root of 21708154 is about 4659.2010044642. The cubic root of 21708154 is about 278.9593771013.

Adding to 21708154 its reverse (45180712), we get a palindrome (66888866).

The spelling of 21708154 in words is "twenty-one million, seven hundred eight thousand, one hundred fifty-four".