21438151 has 8 divisors (see below), whose sum is σ = 24811520. Its totient is φ = 18142488.

The previous prime is 21438103. The next prime is 21438187. The reversal of 21438151 is 15183412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21438151 - 2⁹ = 21437639 is a prime.

It is a Duffinian number.

It is a plaindrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21438101) 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, 18831 + ... + 19936.

It is an arithmetic number, because the mean of its divisors is an integer number (3101440).

Almost surely, 2^21438151 is an apocalyptic number.

21438151 is a deficient number, since it is larger than the sum of its proper divisors (3373369).

21438151 is an equidigital number, since it uses as much as digits as its factorization.

21438151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38853.

The product of its digits is 960, while the sum is 25.

The square root of 21438151 is about 4630.1350952213. The cubic root of 21438151 is about 277.7979960335.

The spelling of 21438151 in words is "twenty-one million, four hundred thirty-eight thousand, one hundred fifty-one".