21798154 has 16 divisors (see below), whose sum is σ = 37843200. Its totient is φ = 9223344.

The previous prime is 21798137. The next prime is 21798157. The reversal of 21798154 is 45189712.

It is not an unprimeable number, because it can be changed into a prime (21798157) 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, 8749 + ... + 10960.

It is an arithmetic number, because the mean of its divisors is an integer number (2365200).

Almost surely, 2^21798154 is an apocalyptic number.

21798154 is a deficient number, since it is larger than the sum of its proper divisors (16045046).

21798154 is a wasteful number, since it uses less digits than its factorization.

21798154 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19797.

The product of its digits is 20160, while the sum is 37.

The square root of 21798154 is about 4668.8493229060. The cubic root of 21798154 is about 279.3443588220.

It can be divided in two parts, 21798 and 154, that added together give a cube (21952 = 28³).

The spelling of 21798154 in words is "twenty-one million, seven hundred ninety-eight thousand, one hundred fifty-four".