21854151 has 16 divisors (see below), whose sum is σ = 35320320. Its totient is φ = 13244760.

The previous prime is 21854111. The next prime is 21854153. The reversal of 21854151 is 15145812.

It is not a de Polignac number, because 21854151 - 2¹³ = 21845959 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 (21854153) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36495 + ... + 37088.

It is an arithmetic number, because the mean of its divisors is an integer number (2207520).

Almost surely, 2^21854151 is an apocalyptic number.

21854151 is a deficient number, since it is larger than the sum of its proper divisors (13466169).

21854151 is a wasteful number, since it uses less digits than its factorization.

21854151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73603 (or 73597 counting only the distinct ones).

The product of its digits is 1600, while the sum is 27.

The square root of 21854151 is about 4674.8423502831. The cubic root of 21854151 is about 279.5833556745.

Adding to 21854151 its reverse (15145812), we get a palindrome (36999963).

It can be divided in two parts, 2185 and 4151, that added together give a palindrome (6336).

The spelling of 21854151 in words is "twenty-one million, eight hundred fifty-four thousand, one hundred fifty-one".