21385151 has 8 divisors (see below), whose sum is σ = 22174320. Its totient is φ = 20599488.

The previous prime is 21385139. The next prime is 21385153. The reversal of 21385151 is 15158312.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21385151 - 2⁶ = 21385087 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21385151.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21385153) 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, 22355 + ... + 23291.

It is an arithmetic number, because the mean of its divisors is an integer number (2771790).

Almost surely, 2^21385151 is an apocalyptic number.

21385151 is a deficient number, since it is larger than the sum of its proper divisors (789169).

21385151 is an equidigital number, since it uses as much as digits as its factorization.

21385151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1753.

The product of its digits is 1200, while the sum is 26.

The square root of 21385151 is about 4624.4081783510. The cubic root of 21385151 is about 277.5688804474.

The spelling of 21385151 in words is "twenty-one million, three hundred eighty-five thousand, one hundred fifty-one".