21649159 has 8 divisors (see below), whose sum is σ = 24772608. Its totient is φ = 18533400.

The previous prime is 21649153. The next prime is 21649163. The reversal of 21649159 is 95194612.

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 21649159 - 2⁷ = 21649031 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21649153) 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, 6714 + ... + 9400.

It is an arithmetic number, because the mean of its divisors is an integer number (3096576).

Almost surely, 2^21649159 is an apocalyptic number.

21649159 is a deficient number, since it is larger than the sum of its proper divisors (3123449).

21649159 is a wasteful number, since it uses less digits than its factorization.

21649159 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3845.

The product of its digits is 19440, while the sum is 37.

The square root of 21649159 is about 4652.8656761183. The cubic root of 21649159 is about 278.7064438906.

The spelling of 21649159 in words is "twenty-one million, six hundred forty-nine thousand, one hundred fifty-nine".