21144156 has 24 divisors (see below), whose sum is σ = 53821824. Its totient is φ = 6407280.

The previous prime is 21144121. The next prime is 21144173. The reversal of 21144156 is 65144112.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 79960 + ... + 80223.

It is an arithmetic number, because the mean of its divisors is an integer number (2242576).

Almost surely, 2^21144156 is an apocalyptic number.

It is an amenable number.

21144156 is an abundant number, since it is smaller than the sum of its proper divisors (32677668).

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

21144156 is a wasteful number, since it uses less digits than its factorization.

21144156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160201 (or 160199 counting only the distinct ones).

The product of its digits is 960, while the sum is 24.

The square root of 21144156 is about 4598.2775035876. The cubic root of 21144156 is about 276.5222730026.

Adding to 21144156 its reverse (65144112), we get a palindrome (86288268).

The spelling of 21144156 in words is "twenty-one million, one hundred forty-four thousand, one hundred fifty-six".