21648351 has 8 divisors (see below), whose sum is σ = 29337904. Its totient is φ = 14195520.

The previous prime is 21648349. The next prime is 21648373. The reversal of 21648351 is 15384612.

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

It is not a de Polignac number, because 21648351 - 2¹ = 21648349 is a prime.

It is a super-2 number, since 2×21648351² = 937302202038402, which contains 22 as substring.

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 (21648301) 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, 58966 + ... + 59331.

It is an arithmetic number, because the mean of its divisors is an integer number (3667238).

Almost surely, 2^21648351 is an apocalyptic number.

21648351 is a deficient number, since it is larger than the sum of its proper divisors (7689553).

21648351 is a wasteful number, since it uses less digits than its factorization.

21648351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118361.

The product of its digits is 5760, while the sum is 30.

The square root of 21648351 is about 4652.7788470977. The cubic root of 21648351 is about 278.7029765102.

The spelling of 21648351 in words is "twenty-one million, six hundred forty-eight thousand, three hundred fifty-one".