21545156 has 12 divisors (see below), whose sum is σ = 37915920. Its totient is φ = 10712040.

The previous prime is 21545149. The next prime is 21545179. The reversal of 21545156 is 65154512.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14330 + ... + 15761.

It is an arithmetic number, because the mean of its divisors is an integer number (3159660).

Almost surely, 2^21545156 is an apocalyptic number.

It is an amenable number.

21545156 is a deficient number, since it is larger than the sum of its proper divisors (16370764).

21545156 is a wasteful number, since it uses less digits than its factorization.

21545156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30274 (or 30272 counting only the distinct ones).

The product of its digits is 6000, while the sum is 29.

The square root of 21545156 is about 4641.6759904155. The cubic root of 21545156 is about 278.2594234852.

Adding to 21545156 its reverse (65154512), we get a palindrome (86699668).

The spelling of 21545156 in words is "twenty-one million, five hundred forty-five thousand, one hundred fifty-six".