21150855 has 32 divisors (see below), whose sum is σ = 41022720. Its totient is φ = 10254240.

The previous prime is 21150847. The next prime is 21150859. The reversal of 21150855 is 55805112.

It is not a de Polignac number, because 21150855 - 2³ = 21150847 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21150859) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5637 + ... + 8606.

It is an arithmetic number, because the mean of its divisors is an integer number (1281960).

Almost surely, 2^21150855 is an apocalyptic number.

21150855 is a deficient number, since it is larger than the sum of its proper divisors (19871865).

21150855 is a wasteful number, since it uses less digits than its factorization.

21150855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14268 (or 14262 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 27.

The square root of 21150855 is about 4599.0058708377. The cubic root of 21150855 is about 276.5514729875.

Adding to 21150855 its reverse (55805112), we get a palindrome (76955967).

The spelling of 21150855 in words is "twenty-one million, one hundred fifty thousand, eight hundred fifty-five".