21118008154 has 8 divisors (see below), whose sum is σ = 31728689460. Its totient is φ = 10541778336.

The previous prime is 21118008143. The next prime is 21118008157. The reversal of 21118008154 is 45180081112.

It can be written as a sum of positive squares in 2 ways, for example, as 18559975225 + 2558032929 = 136235^2 + 50577^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21118008157) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8611339 + ... + 8613790.

Almost surely, 2^21118008154 is an apocalyptic number.

21118008154 is a deficient number, since it is larger than the sum of its proper divisors (10610681306).

21118008154 is a wasteful number, since it uses less digits than its factorization.

21118008154 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17225744.

The product of its (nonzero) digits is 2560, while the sum is 31.

Adding to 21118008154 its reverse (45180081112), we get a palindrome (66298089266).

The spelling of 21118008154 in words is "twenty-one billion, one hundred eighteen million, eight thousand, one hundred fifty-four".