21100154 has 16 divisors (see below), whose sum is σ = 33153408. Its totient is φ = 10052592.

The previous prime is 21100141. The next prime is 21100159. The reversal of 21100154 is 45100112.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21100159) 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, 13859 + ... + 15305.

It is an arithmetic number, because the mean of its divisors is an integer number (2072088).

Almost surely, 2^21100154 is an apocalyptic number.

21100154 is a deficient number, since it is larger than the sum of its proper divisors (12053254).

21100154 is a wasteful number, since it uses less digits than its factorization.

21100154 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1789.

The product of its (nonzero) digits is 40, while the sum is 14.

The square root of 21100154 is about 4593.4903940250. The cubic root of 21100154 is about 276.3303210950.

Adding to 21100154 its reverse (45100112), we get a palindrome (66200266).

The spelling of 21100154 in words is "twenty-one million, one hundred thousand, one hundred fifty-four".