21179154 has 16 divisors (see below), whose sum is σ = 42511392. Its totient is φ = 7034208.

The previous prime is 21179153. The next prime is 21179173. The reversal of 21179154 is 45197112.

It is not an unprimeable number, because it can be changed into a prime (21179153) 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, 4539 + ... + 7934.

It is an arithmetic number, because the mean of its divisors is an integer number (2656962).

Almost surely, 2^21179154 is an apocalyptic number.

21179154 is an abundant number, since it is smaller than the sum of its proper divisors (21332238).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21179154 is a wasteful number, since it uses less digits than its factorization.

21179154 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12761.

The product of its digits is 2520, while the sum is 30.

The square root of 21179154 is about 4602.0814855889. The cubic root of 21179154 is about 276.6747562996.

The spelling of 21179154 in words is "twenty-one million, one hundred seventy-nine thousand, one hundred fifty-four".