21649417 has 16 divisors (see below), whose sum is σ = 24053760. Its totient is φ = 19392912.

The previous prime is 21649361. The next prime is 21649429. The reversal of 21649417 is 71494612.

It is a cyclic number.

It is not a de Polignac number, because 21649417 - 2⁷ = 21649289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21649447) 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, 46528 + ... + 46990.

It is an arithmetic number, because the mean of its divisors is an integer number (1503360).

Almost surely, 2^21649417 is an apocalyptic number.

It is an amenable number.

21649417 is a deficient number, since it is larger than the sum of its proper divisors (2404343).

21649417 is a wasteful number, since it uses less digits than its factorization.

21649417 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 612.

The product of its digits is 12096, while the sum is 34.

The square root of 21649417 is about 4652.8934008851. The cubic root of 21649417 is about 278.7075510310.

The spelling of 21649417 in words is "twenty-one million, six hundred forty-nine thousand, four hundred seventeen".